kramer87gta

iTrader: (1)

Hey Everyone!.. Its been a while!.. But im planning on a rebuild of the 305 this year.

I have an 87 GTA convertible w/305 and im planning on putting in on the shelf this year and giving it the rebuild it deserves.

i have been looking and reasearching for quite some time but have not been able to really get answers to what im looking for. But this is what I plan on doing:

1. Pull the motor and tear completely down
2. take bottom end to shop to have new rings installed, walls rehoned, new bearings installed, crank reground if need be, everything cleaned degreased, and then reassembled and balanced.
3. install new cylinder heads, cam, SLP runners, bbk TB, headers, "high" flo cat, change exaust tubing to 3 inch ?
4. Felpro or Trick flow complete gastket set.

But overall due to the rarity of the car i just want to give it a little more pep, and want to keep the 305 with the car. And looking to build a nice streetable car, 250-300 hp is really all i want for this car, But im confused on which heads to get to accomplish this, I like Trick flow products and saw a build were someone put a set of there 23 heads on I believe, But i know there are other companies out there. As far as the Intake i have heard the stealth ram is nice, or what about First fuel injection systems? Would the SLP runners work well with either of those systems or are they really needed?

I guess those are the general question I have as of now being im not seeing to many threads in realtion to the part I would like to use.

So if you guys have some ideas or anything else to throw my way that would be greatly apprectiated as the rebuild is probably going to start in May.

kramer87gta

iTrader: (1)

Or would it make sense instead of getting new heads to just take the ones I have and spec them to the trick flow heads?

jamon8

iTrader: (3)

if you are not making a bunch of power the stock heads are fine

you really dont need much more than the stock tpi stuff to feed that 305

I would not spend the money on a 305 block if the machine shop says it needs to be bored

d4nk

iTrader: (2)

pick up a 350 block, rebuild it. then do a direct replacement.

I ran a 305 with the trickflow heads, edelbrock lower TPI manifold, SLP runners, and a ported plenum. 24# injectors with a ostrich programmable ecm. Only to be disappointed.

elano

iTrader: (2)

Quoted for truth.

kramer87gta

iTrader: (1)

What kind of numbers where you running? being that is honestly what i want to do with the addition of a cam.

d4nk

iTrader: (2)

I never had the car on a dyno, but my best 1/4 mile pass with that combo was 14.6 granted our local track is 5,800ft elevation so that played a major roll in it.

I had also stabbed a lunati voodoo cam in it spec'ing out at 213/219 duration at .050 256/262 advertised, .454/.468 lift, with the addition of 1.6 rockers.

kramer87gta

iTrader: (1)

hmm intresting, im here in wisconsin so im not sure how much better the time would be and for the most part im just looking to give it more pep, as i have a 03 stang gt that is going to be supercharged so this would be the cruiser of the 2.. :-)

Davidgou

iTrader: (2)

So what's the actual HP on a stock 305 TPI? LB9 to be exact? 'Cause I'm gonna have to fix or replace mine. It threw a rod and I'm in the process of removing it now. I don't have much time, so I do a little here and a little there. Don't have $ either, honestly I just want my car to drive nicely. I don't race it, and it was "fast enough" when it ran fine before. But I'm curious to know. thanks

d4nk

iTrader: (2)

Rock Falls Raceway shows 838ft, Wisconsin International shows 709ft. So with my old combo it would be around 13.5 maybe a little slower up there. So figure high to mid 13's.

d4nk

iTrader: (2)

215 - 220hp for a 1988 LB9

kramer87gta

iTrader: (1)

I would actually be happy with something like that a mid 13 sec car, would be perfect. Im sure there has been much discussion on this but are the chips from say hypertech or anything worth the money?

d4nk

iTrader: (2)

I would stay away from the hypertechs. I was very happy with my ostrich:
http://www.moates.net/product_info.p...roducts_id=169

Can make on the fly adjustments to the computers brain box. There is a huge support section here on TGO to help you get started on programming your own bin's.

kramer87gta

iTrader: (1)

Interesting how difficult is this to use and set up?

d4nk

iTrader: (2)

real easy to install. take the kick panel off the passanger side, drop the ECM, unscrew the retaining plate on the ecm, pull the stock PROM chip, plug the stock PROM chip into the moates.net GP1 chip adapter, plug adapter back into the ecm, route the data ribbon cable to the ostrich, and reinstall. You can plug any laptop/computer into the ostrich that has a USB port. The software required to program the ostrich is free, i used a program called TunerPro available at - http://www.tunerpro.net/

kramer87gta

iTrader: (1)

I was looking the screen shots, I think i will be going this route once the car gets worked on. Ill probably have ask a few questions in the tuning stage as i have never done it before, But being in the IT field im sure i can get through it will some guidance.

d4nk

iTrader: (2)

Glad I could help, if you have any questions feel free to shoot me a PM.

Davidgou

iTrader: (2)

Thanks for the quick response. And if I'm able to rebuild mine stock (for lack of $ to buy any performance stuff), what's a decent gas mileage I could expect? What kind of bolt-on upgrades can I do to it later to the stock engine to gain some HP?

Thirdgen89GTA

iTrader: (5)

Thats only with a manual. With an auto its...less. GM stuck a peanut cam in it. Manuals got the L98 cam, and auto's got the Peanut cam, which is like 190/194 duration @.050" and less than .400" lift at the valve.

Thirdgen89GTA

iTrader: (5)

Assuming you don't go wild with a cam, a mildly cammed 305/350 TPI car will net about 20-25mpg depending on elevation and mods.

My LT1/4L60e gets 19mpg with no 4th gear and no TC lock-up. Bought the swap complete harness/pcm and all. However the transmission the guy had bought did not match the year of the car. And with 4L60E's this is VERY important. They aren't all compatible like 700r4's are for thirdgens.

I have a T56 waiting to go in.

Davidgou

iTrader: (2)

Oh, that's very decent, I can live with that. Man, I can't wait to get that engine out and taken apart to see what it needs. My car needs a lot of TLC to get it back to how it used to look and drive before I let my son drive it daily and the engine got messed up. Thanks again.

Thirdgen89GTA

iTrader: (5)

My old L98 had a Lingenfelter 211/219 cam, stock heads that I had a good valve job on, Arizona Speed & Marine semi-siamesed runners, ported plenum, ported base, Hooker 2055 headers, and a SLP 2 on the left exhaust would get about 20mpg average, about 26 if I was very careful on long highway trips.

If I was having "fun" all week, or got stuck in traffic those numbers could drop fast though.

I later went with a Holley Stealth Ram and wish I had gone for a bigger cam. but the 211/219 lingenfelter cam was VERY nice, stock idle, lots of torque. Pulled strong to over 5,000rpm.

Remember, I had a 350 though. The 211 cam would be a little more radical for you, but it would still be considered a mild cam. if you are going to do ANY work to the bottom end, I'd definitely just find a 350 roller block since you have an 88. Anything from 87 to current sbc would be good. I don't think Gm changed its rotating assembly enough to make compression do odd things for you.

A very popular and well established setup is 350, vortec heads, and a vortec base, either going Holley stealth-ram or staying TPI will net some good HP.

Also, the 5.3L LS engines out of newer trucks make a good buy as they are going for 400-600 right now. Sometimes youc an find a complete engine with harness and PCM for about $700. Thats 315hp out of the box with manifolds.

Davidgou

iTrader: (2)

Man, thanks a lot for that info. I really appreciate it and I'll definitely keep all this in mind. I'm pretty sure I'll have to find me a 350 'cause my LB9 threw a rod and made a small hole on the oil pan. I'll keep you posted.

Thirdgen89GTA

iTrader: (5)

If that the case don't even bother with a 305. 350's are plentiful out there. Look for a TBI 350 out of a suburban or something like that. You could get away with just 22 to 24# injectors, the long block, and a L98 cam which I'm sure are all over for cheap. (L98 22#, LT1 or Ford SVO 24# injectors are cheap) As long as its all in good running shape then you'd be looking at what amounts to an L98, which when running well make about 200 to 210 at the wheels. Though I have seen a stock L98 make 225hp at the wheels with nothing more than a custom tune. the same L98 was trapping about 97 to 98mph in the 1/4 mile.

If you want, you can also look for a Vortec 350 car. You'd then need a Vortec base, and a set of LT1 injectors (LT1 or 24# injectors will work, also L98 injectors will work at 22#/hr) But the advantage of the vortec 350 is that you get higher flowing heads, and along with a cam should be good for a nice upgrade over your 305 TPI car. At least another 40rwhp, possibly more. HSR topped Vortec 350's with the right cam and exhaust will make near 300rwhp.

You've got alot of options open to you right now. Even with the baby cam I LOVE my LT1. Runs strong. The only mods to the motor I have are a cold air intake, hooker 2055 shorty headers, and a SLP 2otL cat-back. And it moves out good enough for me now.

d4nk

iTrader: (2)

can you say thread jacking? open up a new thread!

Thirdgen89GTA

iTrader: (5)

A new thread wouldn't make much sense as both users are dealing with the question of upgrading their 305s. Different reasons for each, similar power goals. So its still relevant to the topic.

Davidgou

iTrader: (2)

Dude, chill. No harm intended. The thread is about a 305 Build. That's what we're all trying to learn about. What's the point in opening a whole bunch of threads over the same questions, unless of course the Moderator thinks I'm wrong. Like I said, no harm or "hack" intended here. One thing led to another, that's all. But sorry if I offended anyone. I've been a member for a long time and had never been "kicked out" of any thread before...but I guess there's always a first time.

cal30_sniper

iTrader: (16)

Back to the OP...

From what I'm reading, and what others have told me on here, if you want a better flowing/aluminum head, go with the 113 Aluminum L98 Corvette casting vice the Trick Flow 305 head. The 113 flows almost as well with a smaller port, meaning higher velocities and better throttle response. I'll be doing a carbed 305 with a Comp XR258-HR12 and 113 D-port heads (these are also basically the same head as on the ZZ4 crate motors). I feel that as long as you don't go amazingly radical on the cam, you'll never see the benefit of a Trick Flow head (especially since they cost over $600 more than a good pair of 113s).

Just my $.02, that's what I'm looking at right now.

As far as gas mileage goes, I knocked down 27-29 highway MPG out of my old T/A, and the same out of my Formula with a carburetor. Both are TH700 cars with 2.73 rear gears. Around town gets as high as 20 as long as you refrain from getting frisky away from the stop lights. Best I've had was 33 mpg at steady 55 mph out of my Formula. Exhaust, air intake (i.e., filter and assembly, not the actual intake manifold itself), and ignition are your big keys to efficiency. Strangely enough, with more efficiency, also often comes more power.

-Levi

kramer87gta

iTrader: (1)

OK so this might be a rookie question, but what should i look for in a head?? i mean overall the bottom end is going to be left as stock, just freshened up with new rings, bearings, and such. i guess im thinking about it to much as the 305/350 parts are interchangeable for the most part. I mean would it just make sense to maybe port and polish the heads that i already have? I might put new springs in it to handle a cam.. which leads me to my next question, if i port and polish the stock heads what would be the best overall cam to choose from as far as duration and such, i think having something in the midrange for RPM would be best like 1800-5000 or close to that. I was looking at something like this:

http://cgi.ebay.com/ebaymotors/COMP-...Q5fAccessories

and this TB:
http://cgi.ebay.com/ebaymotors/1985-...Q5fAccessories

d4nk

iTrader: (2)

If you already have a roller motor you can re-use the lifters, as that will save you a nice chunk of change. As far as the heads, what are the last 3 digits of the casting numbers? Located under the valve cover. After porting, polishing, valve job, rocker studs drilled and tap'd, bowls blended the whole nine yards you will be pretty deep into it, where as you could just get a set of some world heads for that. Before anything you need to decide weather you want to keep the 305 or go 350.

The cam you listed would work well in a 350 but might be a bit big for a 305. If I was still running EFI I would look into the comp xfi grinds. With the fuel injection generally you dont want to get carried away on the duration, you will want to go for lift. Maybe something like this for a 305:
http://www.compcams.com/Cam_Specs/Ca...?csid=208&sb=0

Heres a cool little program you can tinker with made by comp cams:
http://www.compcams.com/camquest/

kramer87gta

iTrader: (1)

OK makes sense, i figured i would just either get the heads redone, being they have not been touched in 22 years, and need a valve job as the car is buring a little oil. But if it makes more sense just to get something new and complete what type of heads by world would you recommend? i have heard of them before i know they make good stuff.

That sorta makes sense with the CAM, i have been reading a cam article from this site and it sorta makes sense, im looking for something that gives it a little more of a lumpy idle but nothing obnoxious. In looking at all those other part numbers would you recommend going with all of those items, as in valve seals etc etc etc. also what is meant my matching heads? probably another dumb question but i would think mine would be matching.

But due to the fact there were less then 175 produced im going to just work with the 305 being it was the motor that came with the car and would like to keep it all together.

cal30_sniper

iTrader: (16)

IMHO,

The cam you selected is way too much for what you're trying to accomplish here. There are a few important points to keep in mind which prompt me to say this.

1. You're going back in with a factory bottom end. This isn't a motor that you're going to want to spin a lot of RPMs or anything, so why use a cam that has an operating range above much of the range you will see in street usage? A higher power band also introduces other problems with torque converters and gearing, keep that in mind as well.

2. You have a 305, not a 350. The cam operating range for a SBC cam will be based on a 350. Hence, the operating band for the same cam in a 305 will have shifted up (i.e. 2000-6000 rpm for this cam). The opposite would happen for say, a 383, where the same cam would be milder in application.

3. Your motor is a TPI, which means that it will respond much better to a cam that produces a lot of low end torque. The TPI itself is very rev limited, and falls on its face in the 4500-5000+ rpm range.

4. If I understand correctly, you wanted to use the car as a driver/cruiser rather than a serious racer. With a cam that produces torque in a lower RPM band, you will get much more seat of the pants performance, sacrificing only top end power you'll never be able to get to. Also, a shorter duration cam that operates in a lower RPM range will get much better mileage, another important thing to keep in mind for a driver.

That being said, I would suggest something along the lines of the CompCams 264HR-12 or 266HR-12. A 262HR-12 might work really well, but could be a little too mild for your expectations. I don't know what cams tend to play well with the TPI computer, but all of the above are listed as Computer Controlled compatible cams, so they should be good.

The factory heads could be worked for better flow and power. If you're capable of doing the work yourself, that might be a great option. A set of vortec iron heads, or L98 heads would be an excellent upgrade, and would flow much better due to their bigger valves and more efficient design. I went with 113 Aluminum L98 Corvette heads due to their lighter weight, decent flow numbers, and 58cc combustion chamber.

For the 305, the combustion chamber is going to be your limiting factor in head selection. Your '87 305 has a 9.3:1 combustion chamber, which is actually pretty good compared to the earlier 305s, but it does this with a 58cc combustion chamber. Be wary of stepping up to a 64cc chamber head, as this is going to hurt your compression ratio. Also, you have to be careful of 350 heads on a 305 due to the smaller bore diameter. You don't want valves kissing cylinder walls.

There is a wealth of information on this forum on 305 head selection. In fact, I believe there's even a FAQ on it. Read all you can, and then make the informed decision based on the advice of others who are doing it, have done it, and would or would not do it again. Magazine and advertising hype sells parts, but research and experience builds fast cars.

That's about all I can think of for now. Remember, a small cam with a well matched set of supporting pieces will be just as powerful as a monster cam in a poorly matched combo, it will be much more efficient, and a whole heck of a lot more fun to drive. You've got a good start, keep up the research and be patient, you'll find what you're looking for.

-Levi

d4nk

iTrader: (2)

The corvette 113 heads would be a good choice as they are aluminium and probably better flowing. Might have to do some searching to find them. The 113 refers to the last 3 digits in the casting numbers. Only thing with that is if you do find a set you may have to go threw them anyway with new seals and what not.

The world heads are just a stock replacement head, however they come with screw in rocker studs, and better springs for up to .560 lift, and a 1.94 intake valve apposed to the 1.84 in your stock heads.

http://www.summitracing.com/parts.aspx?sku=WRL-042750-1

musclecar70sfan

iTrader: (1)

Sorry if I'm reviving an old thread but I'd like to subscribe to this thread considering that my 91 Trans Am convertible has a 305 TPI. I'm pretty much in the same boat as you Kramer, want to keep the original flavor but with a little bit more spice. I'd like something to beat those ricers and some foxbodies at redlights.

And mid 13s with a 305? (according to d4nk) That's not bad at all, if I could squeeze those numbers out of mine, I'd be very happy. What does that 1/4 mile time mean with 0-60 times? I have the front end of my car taken apart (engine is still in) so I was thinking that with the car the way it is I'd replace the cam. Is it possible to replace the cam shaft without pulling out the engine?

I don't care what kind of numbers the engine is putting out. Doesn't matter if its putting out 150 hp, as long as the 1/4 mile times are good lol.

What kind of gains should this give a 305 TPI?
http://www.summitracing.com/parts/SLE-20002