When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The egr side should be removable. You can measure the port opening too and compare to the 1204 specs.
1204 1.99 in. x 1.23 in
Even if the plate isn’t removable from the 1204 tin snips or drill a hole in the passengers side.
or ask what this guy ended up using. https://www.thirdgen.org/forums/tpi/...-manifold.html
Last edited by Tuned Performance; 02-12-2019 at 04:20 PM.
Vinny also keep in mind, biggest isn't always better and knowing where to remove material and where not to are the key to a "good" port job porters will try here and there and measure the results on a flow bench. Dont get me wrong I'm not bashing, as so far what I see will make improvement for you. even A/market manufacturers get it wrong Edelbrock for one the 3860 is a good high flow base then they make the 3817 - Vortec TPI base and it flows about what the stock GM base does you would think a company that makes "performance" parts would do R&D before selling them. - keep going
If you are going to do a custom tune then I would say go ahead and play with the injectors, if not, I would recommend just putting it all together and not changing too many things at once...
That was our saying when I raced go-karts...only one change at a time. I was only wanting to change because I am going to be pulling them out anyway, I really don't want to mess with a tune if I don't need one. I know you went through quite a few before getting it right. I will check my budget and see if the new Delphi's are in there. I must have one of the few great working Multec sets but you know how it goes, right after I put them back in...they crap the pot!
I do know of them and checked out their site but that was about it. I posted a pic in one of my previous post up above of a before and after that I got from their site. I might reach out to them just to get some info on cost and such. It looks like a pretty cool process they do.
Vinny also keep in mind, biggest isn't always better and knowing where to remove material and where not to are the key to a "good" port job porters will try here and there and measure the results on a flow bench. Dont get me wrong I'm not bashing, as so far what I see will make improvement for you. even A/market manufacturers get it wrong Edelbrock for one the 3860 is a good high flow base then they make the 3817 - Vortec TPI base and it flows about what the stock GM base does you would think a company that makes "performance" parts would do R&D before selling them. - keep going
You would think they would, especially a performance parts co. Thanks for the words of advice Zman. It sounds like you have a clue. I have been trying to figure a DIY flow tester. I don't have access to the real thing.
I do know of them and checked out their site but that was about it. I posted a pic in one of my previous post up above of a before and after that I got from their site. I might reach out to them just to get some info on cost and such. It looks like a pretty cool process they do.
If you do speak with them, let us know the cost, I've been curious about that, thanks
I was at HF yesterday and standing in the checkout line I found a digital inner and outer micrometer. Yes I know it it a Pittsburgh product but for what I am doing it will be just fine. I would not want to trust it on a crank journal but it sure works sooo much better than the tape measure I have been using. It was a whopping $10 I am trying to maintain some consistency on the port openings and this $10 well spent mic will do just the trick. All the openings are within .01 of each other. I guess the tape measure worked o.k.
Thanks for the education Biz...I feel like an idiot...it is printed right on the tool!.
Does any of you guys following this know the port opening dimension is on my 081 heads? I am looking for a measurement like 1.125" x 1,80".Maybe one of you have a set of heads laying around and can give me a number>
The egr side should be removable. You can measure the port opening too and compare to the 1204 specs.
1204 1.99 in. x 1.23 in
Even if the plate isn’t removable from the 1204 tin snips or drill a hole in the passengers side.
or ask what this guy ended up using. https://www.thirdgen.org/forums/tpi/...-manifold.html
FWIW, the 1204 is what I used; I simply drilled out the spot weld and the plates fell off.
I had today off so I was able to make some progress. I work tomorrow and that should be it for my weekend work! At least for now.
I got one side fully complete. I had some finished prior but I put a good 3 hrs and finished 4 ports all the way through. I think I am going to have about 8-9 hrs total in the one side. It is going good, being careful not to cut to much and have not gone through anywhere! When you look down the ports it really looks like it is going to flow really well. I wish I had access to a flow bench. By no means is it perfect but it is leaps and bounds above what the untouched side looks like. I am not definitively not a pro at this but thus far I am satisfied with how it is turning out.
Those cutters I bought do not disappoint. I may not be making the ports as large as possible but it sure is removing material!
Here are some pics from both sides where you can see through. It is hard to get a goot pic looking through.
That is not a crack, although it sure looks it. It is a small shadow fron the casting mark in the runner. I took the pic after I washed it off and the water makes it look like a crack.
One more day to find and I can finish this manifold up!
I want your opinions guys, Do I make room in my budget for the new injectors? I probably can swing it but I want your opinion on if I throw my working Multecs back in. Doesn't Southbay give members 10% off any purchase?
One more day to find and I can finish this manifold up!
I want your opinions guys, Do I make room in my budget for the new injectors? I probably can swing it but I want your opinion on if I throw my working Multecs back in. Doesn't Southbay give members 10% off any purchase?
I am in (or on) Jupiter.
You are right about the cast thing, but with my limited knowledge of this I have heard that the SLP's and such are shorter and fatter so more CFM's can get through. Maybe someone else here knows for sure. I did not know that AS&M made the TPIS, that makes sense as they look the same.
Your set up is going to end up similar to mine. I have the TPIs manifold and I paid a pretty penny for it. According to the guy I spoke to at AS&M (they still make them) made the runners for TPIs and I believe he said Edelbrock made the lower intake for TPIs (they are the same). You might want to look and see if you can find an Edelbrock lower intake. The guy at AS&M was super friendly you can call and confirm about the manifold.
Vinny also keep in mind, biggest isn't always better and knowing where to remove material and where not to are the key to a "good" port job porters will try here and there and measure the results on a flow bench. Dont get me wrong I'm not bashing, as so far what I see will make improvement for you. even A/market manufacturers get it wrong Edelbrock for one the 3860 is a good high flow base then they make the 3817 - Vortec TPI base and it flows about what the stock GM base does you would think a company that makes "performance" parts would do R&D before selling them. - keep going
I was still able to get 356 hp out of a 305 and 380 hp out of a 383 to the wheels with an edelbrock 3817 base ported to match the siamesed SLP runners I ran on it. Minor cleanup on the cylinder head end to match the stock vortec port, debur around the injector boss thinning it slightly and opened up the runner end to match the ported SLPs. The 383 had the same cam as the 305. Made ALOT more toque and put its peak HP down 500 rpm earlier.
That being said the Indmar marine intake I am running on my 350 is a much better intake for making HP. It has runners that average 5" long and had alot of meat to make them match my 215cc head ports.
Your set up is going to end up similar to mine. I have the TPIs manifold and I paid a pretty penny for it. According to the guy I spoke to at AS&M (they still make them) made the runners for TPIs and I believe he said Edelbrock made the lower intake for TPIs (they are the same). You might want to look and see if you can find an Edelbrock lower intake. The guy at AS&M was super friendly you can call and confirm about the manifold.
How do you like your setup? Did you also modify your plenum?
I did speak with a guy at AS&M earlier in this project, but I did not ask about a manifold. I did not want to just buy one for this I wanted to do the work myself and as you said any aftermarket manifold you are going to $$.
I was still able to get 356 hp out of a 305 and 380 hp out of a 383 to the wheels with an edelbrock 3817 base ported to match the siamesed SLP runners I ran on it. Minor cleanup on the cylinder head end to match the stock vortec port, debur around the injector boss thinning it slightly and opened up the runner end to match the ported SLPs. The 383 had the same cam as the 305. Made ALOT more toque and put its peak HP down 500 rpm earlier.
That being said the Indmar marine intake I am running on my 350 is a much better intake for making HP. It has runners that average 5" long and had alot of meat to make them match my 215cc head ports.
Those are some pretty impressive numbers on the 305! I am hoping to gain 40 hp with this build so If I get that I will be happy. I do not plan on touching the heads just the TPI system.
Last edited by vinny R; 03-30-2019 at 06:41 AM.
Reason: typo
Good job Vinny! I love the look of the factory TPI
Thank you...me too! Hey if this works out you should do this to the engine you have waiting to go in. I finished the port work yesterday and I an ready to put the coat of aluminum paint on today. I will post my finished pics this weekend so I am getting close. It is looking good, I am leaning towards taking your advice and me and a friend may go out to the track and give her a run before I switch out the parts. He has a MeToo mustang GT so we will do a good ole bracket race!
Alright, I am finished with the port work. It was a lot of fun and learning but by about the 6th port I was getting to where I wanted it done. I walked away from it for about a week and then got my second wind and finished it up! I got about 20 hrs in it and have no regrets that I did not just buy one. This was a learning project for me. I was able to see first hand where the restrictions are in this system, and work my porting accordingly. I took the advice given to me by the OP's in this thread and took that info and ran with it. I hope you all will like the outcome of my work.
There was a major restriction on the left side of each pot inlet, the runner side. It stuck out at least 1/8" or better. You can see it in the before pics in this thread. I really went after this side and pretty much removed it all. I only opened up the right side slightly, enough to get the casting marks out. The metal gets thin as you go down the port so I was careful not to remove to much from that side. You can still see a remnant of the casting mark as I was afraid to remove to much material. I used one of those magnetic bolt retrievers and tapped on the walls to get an idea if it was a thick area or not.
On the other side I was able to really smooth out and remove a decent amount of material from the right side. This side looks thick but when I tapped on it it did not sound that thick so I was careful. The bottom of the wall on this side was rounded at the bottom so I took out a decent amount in this area which in turn made that side larger The left side I opened up quite a bit. I was able to smooth out the bend on the left side and make the port width larger. When I look down the port I can really see where It is a much straighter shot for the air to flow.
I see in some of the OP's that I probably should have just bought one of the aftermarket bases. While I have never seen one in person I am not sure how much more I would get out of those. From everything I see that I did to this base it should FLOW! I am not looking to support 300+ HP so I can't see the benefit in spending $500 or more on a base. Maybe one of you guys could tell me am wrong in this thinking. My Plenum, Runners and Base all mach up to a 1.63 ID now.
I still have I few more parts to order, a new EGR valve and since I did not spend that $$ on a base. some new injectors will be in the budget now. New socket bolts for the runners. I got all my gaskets including the TB set. I will get the rest of the parts this week so in another couple weeks the parts will be swapped...getting excited!
Last edited by vinny R; 03-31-2019 at 07:44 AM.
Reason: pronunciation
Thank you...me too! Hey if this works out you should do this to the engine you have waiting to go in. I finished the port work yesterday and I an ready to put the coat of aluminum paint on today. I will post my finished pics this weekend so I am getting close. It is looking good, I am leaning towards taking your advice and me and a friend may go out to the track and give her a run before I switch out the parts. He has a MeToo mustang GT so we will do a good ole bracket race!
. Sold my TPI setup but had a stock TBI intake bored out and cleaned up by a member here he done a great job.
How do you like your setup? Did you also modify your plenum?
I did speak with a guy at AS&M earlier in this project, but I did not ask about a manifold. I did not want to just buy one for this I wanted to do the work myself and as you said any aftermarket manifold you are going to $$.
I am very happy with the way it turned out. The plenum was ported. and I have a Holley airfoil also. I think the airfoil is a must. I think you will be happy with the outcome.
I probably missed it but is this a 5.0 or 5.7? I didn't read through all the posts. There was a web site I found (don't remember which one) and it seemed like some very good info in it and it said the factory throttle body is good up to 400HP. Correct me if I am wrong.
I am very happy with the way it turned out. The plenum was ported. and I have a Holley airfoil also. I think the airfoil is a must. I think you will be happy with the outcome.
I probably missed it but is this a 5.0 or 5.7? I didn't read through all the posts. There was a web site I found (don't remember which one) and it seemed like some very good info in it and it said the factory throttle body is good up to 400HP. Correct me if I am wrong.
Ramjet 502 uses the same TB and makes 502 hp. Those gain power with a bigger TB but still move enough air to make 500 hp.
I am very happy with the way it turned out. The plenum was ported. and I have a Holley airfoil also. I think the airfoil is a must. I think you will be happy with the outcome.
I probably missed it but is this a 5.0 or 5.7? I didn't read through all the posts. There was a web site I found (don't remember which one) and it seemed like some very good info in it and it said the factory throttle body is good up to 400HP. Correct me if I am wrong.
I do have a 305 and I have heard the same info as you guys where our stock TB can handle those horses. I do have an airfoil already in place, not sure the brand, it was in the car when I bought it.. If you remember that site be sure to post a link, I always like doing my homework on this stuff.
I do have a 305 and I have heard the same info as you guys where our stock TB can handle those horses. I do have an airfoil already in place, not sure the brand, it was in the car when I bought it.. If you remember that site be sure to post a link, I always like doing my homework on this stuff.
I have an update to my project. For those of you who are still following this I did say in my first post that this could take awhile, well it is!
The car is in the shop. I dropped it off Friday morning and will pick it up Monday afternoon. I took tomorrow off, I have to drop off the remaining parts I cleaned up and told Jason I would run around if needed for any parts I may have forgotten. I went by his shop Friday afternoon to pick up my TB, fuel rail and bolts. I also picked up one of my valve covers which needed some JB welding. He had it all torn down Friday and I was quite pleased with what I saw under the manifold. I was afraid it might have been a sludge motor but that is not the case. Yeah! I will take a pic Monday morning before he starts putting it back together. Today I will finish Ceremic Coating the rest of the parts before I bring them tomorrow. I have done this to all the parts prior to putting the on. I hope this will allow me to just wipe clean the engine with a microfiber dusting wand..
These are the rest of the parts I cleaned up. The fuel rail I polished first. I painted the fuel lines only. They were already painted as I could tell my manifold had been removed by one of the 7 PO's. I then cut red vinyl 1/8" strips and layed them on the raised part of the polished rail. I like the look of the new Delphi Injectors, the chrome and black fit my decor. I was going to polish the TB but in looking at it what a PITA that would be. So I just cleaned it up so it has a new look and used some metal polish with a brush to get in all those tight areas. I painted the TB plate and will sand off the Rustoleum Sunrise Red paint on the raised TPI lettering. I used Rustoleum 2x paint and primer satin black on the bolts. It sticks great and gives a really nice look when everything is assembled
I started this to get some performance from my air starved TPI, but I also knew this was a great opportunity for me to clean, paint and replace some parts that bothered me by the way they looked.
Last edited by vinny R; 05-05-2019 at 06:52 AM.
Reason: pronunciation
O.k. Picked up the car on yesterday. I got a stomach flu Mon and was indisposed for a couple days.
So I will start with I think what I set out to do I have accomplished, man does she ever breathe! I first noticed the sound when I started it up, throatier, deeper and a touch louder. I walked to the back and I actually feel the exhaust hitting my shins. This thing pumps some air. When I rev the engine it sounds smooth and powerful with no more rasp sound when you let off the gas. Now to the performance, well I did not get to drive it but about 3 miles home, still was not feeling well yesterday and will get to the side effects of my build which will limit my driving for the short term. The performance is awesome! It did move the power band to the higher RPM range, but it seems to be an increase in the overall power of the engine. I probably lost some of the 305 "grunt" but the difference on the upper end is night and day. We all know to well that @ 30 mph with the auto you step on the gas it sounds like a vette and goes like a "chevette". I did this yesterday and she just took off like a proper camaro should, it even sounded better doing it. It just seems that she has gained the power where I think you can get more usage out of. Another thing I noticed is it seems to run less RPM @ 55 mph. More Air baby! This is the 1st real seat of your pants improvement I have made to this TPI 305. This most definitively woke this little 305 up!
The bad, My new set up is pumping so much air that the idle is up too high, about 1K in gear. I did do the iac reset and it is all the way closed and the throttle stop all the way back I can here the air intake at idle now. It is running too hot. went up to 230 yesterday on the way home. She used to run @ 200 and 220 max with the a/c on. I think she is running lean, it has that lean smell to it especially on cold starts. I can just imagine that the amount of air being pumped in that the mixture ratio cannot be right. I am sure the injector perimeters will need adjusting as well as to amount of air being fed. I think the hot condition is a direct result of the above not being right. The idle bounces some at start up, kinda like the computer is moving the IAC try to find the right mixture. The other downfall is there is no room for the large wire harness on the pass side we had to stretch it some so it sits on top of the VC, i really don't like this and need to figure something out.
I think when I get it tuned right I will find more of the grunt come back and maybe some more on the top end. I know the tuning on this is a BIG factor on the way the engine performs. Tunned Performance I think I need your help!
So my overall view of the out come where I am now is I am by no means right yet but what I did is giving me the performance benefit I was looking for so this was the right way to go.. I knew it would need some tunning so i was not disappointed that it is not perfect. I am very happy with the performance. I am also trying to be honest on the good and bad for those of you following. Also remember this is all running through a stock single 2.25" pipe with the factory "y" pipe. Cat removed.
I am working on refinishing my stock valve covers and ordering a gable for a tune. Those aftermarket valve covers have become a problem sooner than expected. The pressure on that harness is pulling on the IAC plug. I push it in (my clip is broke) and after I drive the plug is pulling out. I also have 2 of the plastic sleeves broken on that connector so if you wiggle it the idle moves up and down. I have ordered a new connector. 2 aftermarket products that are larger sharing the same space, one has to go.I will post the completed photos when I swap those covers out. I also will check the seal of the tubes as the idle is high and that could be a vacuum leak. There is no visible leak. What is the best way to check the seal @ the manifold and the runners? A punk with smoke? My problem could just be that connector. It is also hard (long) to start when cold. I think it needs more fueling. Fires right up when up to temp. It ran right about 200 on my spin around the block.
I have been tinkering a little and took her out for a spin yesterday and WOW! I rolled on the throttle At 35mph and she downshifted and pulled all the way to 5K. What a feeling! There is power in those RPMs now. It also seems much smoother on acceleration and quicker getting to the higher RPMs. She does have some hesitation and some "stumbling" here and there but I think that will come out in the tune. I stopped and talked to a friend on the way home and when I started the car he thought I was running race gas by the smell of it.
I wanted to share this with you guys also. Look at those small "volcanos" forming on the wall in the plenum!. My large holes behind that wall are completely closed up! The exhaust gas has created these so it can push it out from the closed passages. Anyone ever seen this before?
It is those small piles that look like poop an the top of the wall, Iit was hard to get a good pick.
I found the reason for the high idle, I have a air leak at the bottom of the drivers front 2 runners. The large valve covers made it difficult to get at the bottom bolts, the ones in between the 2 tubes.
I am going to order a new set of gaskets just incase but I think we can just re tighten the bolts with the covers removed. We had to have the runners lose and wiggle the large covers on.
Below is a pic of my stock covers getting the make over. I will swap them out and should be able to fix the air leak. I also ordered a new IAC connector which is the inconsistent idle i have been experiencing.
I LOVE IT, I LOVE IT....DID I MENTION I LOVE IT!I
I picked up the car today and it was running so good i put some gas in and went for a short cruise.The thing is killer! It runs soooo good, idles great now and the smell went away...for the most part. We put the stock valve covers back on and Jason took the runners off and just went through the process again and the runners are sealed tight now. It also took the tension off the harness on the passenger side so it is not pulling on any of the sensors now. I got a new IAC connector to replace the broken one but it seems fine now. What a difference in overall performance of the engine. it accelerates now when you give it some gas, it sounds like it has power now and it will light up the tires quicker if you jump on it. I do believe it needs a tune, has some smell still there and hesitates from off idle to power kick in. Speaking of off idle, it was mentioned above about this I think by Vader that the plenum wall I removed was put in so this was a stable transition, he also said GM could have done this with a tune, not a restrictive wall. He was right on, my car is smooth in this transition just need to tune the hesitation out. Drveability, man there is no side effect on this by what I have done. IMHO i believe i have enhanced it with this build. I am really glad I put new injectors in, the idle is smooth, like a new car, it was not that way before. The power is smooth also from the new injectors.So as you guys who are still following this and did not give up on me thanks for all your help and advise on this build, I think I did a good job of taking it all in and coming out with something that I feel proud of every time I start her up. I wish you guys could have seen the smile on this 53 year olds face during my cruise!
I hope you guys like the look also. I wanted to use stock parts and the runners were the only thing after market on the intake. One of my goals was to enhance the look of the engine and make it look new with some dressup along the way .Everything (mostly) you see has either been painted or vinyl. The top of the TPI is a vinyl wrap along with the dizzy cover. I will tell you it runs and looks new!
I will be working with a member here on the tune, I got a cable and will try the whole data logging thing. I have a Hypertech chip in it but I think it needs a dialing in. I am new to Tuner Pro but hopefully I can figure it out and get Brian the info needed.
I would like to make a few observations I noticed along the way:
I really don't think if you just buy runners, no matter the brand, I don't feel you will get the seat of your pants feel. I think the fact I did the plenum and base is why. Wether you buy a base or port it yourself it needs to be part of the package.
Everyone should change their injectors. These cars are old and I actually thought mine were good. I was wrong. I had at least 2 that were not right.When I cleaned my old runners 3 ports had carbon still caked on the ports.
Anyone thinking on pouring Seafoam in your PCV valve...please don't waste your time. The carbon is so caked on everything from the injector boss back all this will do is maybe clean the whole in the base were the Seafoam comes out. I had to do multiple cleanings with an industrial cleaner with hose rinsing to get those intake parts clean.
I think this is where you should start if you want to lay the ground work for power beyond the "free mods"
Congrats on a great job!! I really like mods like these. Engine looks really cool. Glad to hear the engine really comes alive. Thanks for the great documentation along the way. The tune is a great idea.
Nice work Vinny! ....looks great too. Glad you're enjoying the performance! Got your text btw......had a graduation party for my stepson yesterday, was pretty busy!
Very nice work, looks great! Sounds like the gains were well worth it. I actually just installed AS&M runners and new injectors on my car too. Already had a ported base & plenum installed but was running stock runners. The tune should improve your set up also. I just took my car out for the first time to datalog and it is now lean from 2000 rpm up. Working on my tune now. Learning TunerPro is not too bad with all the info on this forum.
Were you able to correct the off idle stumble you described with a tune?
I did almost exactly what you have done to your car and have the same off idle stumble. I have all the cables and software and hardware for tuning-just a general lack of knowledge on my part on the subject.
I agree with the improved power. Mine pulls pretty hard to 5500 rpm and gives a good seat of the pants feel where before it was maybe a little sluggish. I've been driving the pee pee out of it and now that the weather is cool, the T Tops are coming off!
Were you able to correct the off idle stumble you described with a tune?
I did almost exactly what you have done to your car and have the same off idle stumble. I have all the cables and software and hardware for tuning-just a general lack of knowledge on my part on the subject.
I agree with the improved power. Mine pulls pretty hard to 5500 rpm and gives a good seat of the pants feel where before it was maybe a little sluggish. I've been driving the pee pee out of it and now that the weather is cool, the T Tops are coming off!
Not yet, I never have been able to datalog the car. I have been having one issue after another and the latest was my laptop crashed that I had Tuner Pro RT loaded. My new laptop will not allow me to download the software again as windows 10 is in safe mode. I have no knowledge of how it works also and got to the point of connecting to the car and then the computer crashed. I have talked to another member here and he referred to it as "witchcraft" to get it to work. My off idle stumble has gotten better on it's own after I drove it on a few long drives. It is still there but I have noticed when the car is up to temp it almost fully goes away. I see you got a 5.7 Hawgtied, I heard you will get even more of a benefit from these mods as the original TPI was designed for the 5.0 and gains are greater when done on the 350
My buddy has a laptop with TP loaded so I am going to borrow it and see if I can get my car to connect. I am using the Moates cable.
I'm still learning the "witchcraft" of TPI tuning! Lol I'm to the point where I need to data log my car. I'll let you know what I come up with so maybe you can use it too.
Were you able to correct the off idle stumble you described with a tune?
I did almost exactly what you have done to your car and have the same off idle stumble. I have all the cables and software and hardware for tuning-just a general lack of knowledge on my part on the subject.
I agree with the improved power. Mine pulls pretty hard to 5500 rpm and gives a good seat of the pants feel where before it was maybe a little sluggish. I've been driving the pee pee out of it and now that the weather is cool, the T Tops are coming off!
Adjust your TPS voltage to be about 0.5-0.6 volts at closed throttle. It has fixed a few off-idle stubles on cars I have messed with. Also verify the timing is 6* on a stock engine. You can experiment up to about 10*.
02-12-2019, 11:28 AM
you would think a company that makes "performance" parts would do R&D before selling them. - keep going 
I am by no means right yet but what I did is giving me the performance benefit I was looking for so this was the right way to go.. I knew it would need some tunning so i was not disappointed that it is not perfect. I am very happy with the performance. I am also trying to be honest on the good and bad for those of you following. Also remember this is all running through a stock single 2.25" pipe with the factory "y" pipe. Cat removed. 
