sublimed

I知 in the middle of a little project. I ended up needing to rebuild my transmission. After I got under the car I realized how bad my stock suspension was. I then redid all of my suspension.

I knew the car had a butchered Y pipe and it bothered me. I found a used magna flow Y pipe. Cut my old Y pipe off. I realized why I had a butchered Y pipe. The Drivers side is a HO manifold and the passenger side is a non HO manifold. I now have some decisions to make.

I can swap out the manifold to the HO manifold. I have the manifolds.

I have Edelbrock emissions headers that I could clean up and install. I would need a Y pipe fabricated.

I could finally purchase a full exhaust with no name long tube headers locally and Install.

Now comes my question/problem. I知 in Phoenix and this is prime driving time for my car. I was planning on doing some major work this summer when I do not drive the car. This includes new heads/intake/Cam.

Will I be killing performance if I do the edlebrock or HO manifolds to the point I should just do the headers now?

I really just want to get it back on the road and I知 tempted to just do the path of least resistance now.

Firechicken82

I had really good luck w the Edelbrock headers for years. They're not the greatest but I would assume better than manifolds. The y pipe is a big restriction. Dyno don makes a y pipe that corrects this. The HO manifolds may flow well but I don't know much about them. You need to think about what heads your gonna do, certain heads had ports that won't work w your manifolds. To be honest, if your doing the top end of the engine your likely gonna need a high flowing exhaust and I'd bet any manifold will be a restriction at that point. Even the edelbrocks at 1 5/8 may be a restriction. I may be wrong w that, it really depends on the mods your planning.

vinny R

I doubt you have one HO manifold. I don't see your engine listed but you probably have the LO3 exhaust and manifolds. The drivers side of your Magna-Flow Y-pipe will bolt up to the drivers side manifold but the passenger side won't. It ends up a few inches short on that side

If you are going to do a complete top end I would not do any exhaust at this time. Get a complete exhaust system to match the performance parts you are adding. I would not do any exhaust at this point if it were me. If it was me and I REALLY want to drive the car now, I would put the CUSTOM Y-pipe back and enjoy the driving season. If you can forgo this driving season, which I would recommend, now that you know the exhaust needs a replacement, I would start the top end and have a real nice driving season next year.

blacksunshine'91

iTrader: (10)

You said you have the HO manifolds. Do you have the spacer that attaches to the passenger side? If so, then the magnaflow y-pipe will fit the HO manifolds fine.

If not, they you'll need that spacer to make it work and it would probably be better to just reconnect the current modified pipe for the time being until you know for sure what you want to do.

LAFireboyd

iTrader: (3)

Butchered how? Was there a cast iron spacer between the passenger manifold and the y-pipe? Without that spacer, the y-pipe will appear jacked up because it won't be fitting the manifold properly.

This would probably be the simplest thing to do if you want the car back on the road quickly. But here, too, you'll need that spacer between the passenger side manifold and the y-pipe. If you don't have one, then you can probably find one on ebay.

In addition to his own brand of headers, Dyno Don makes y-pipes for Edelbrock headers, and he's coming out of retirement right now to begin a run of his headers and y-pipes, so if you want to go this route, the timing is right, but get in touch with him soon. Also consider the cost and production time, because that could affect getting the car on the road asap.

Financially, this would probably be the best thing to do for the long run since you'll be upgrading the engine soon. But it's probably not the way to go now to get the car back on the road asap.

If you mean using the shorties or the manifolds for the long run with the modified engine, then it might not be best, but the shorties aren't going to kill performance. For the current engine, either will be an upgrade.

Working with what you have is the quickest way to get it back on the road asap.

sublimed

Butchered as in it was two stock Y pipes welded together to make this one. It was leaking and sounded poor. The cat is highflow and everything back from the cat is 3.5 inches and a couple seasons old. The passenger side had a doughnut spacer. I have the larger spacer that I purchased with the HO manifolds and y-pipe. The drivers side has a larger output and the casting number is the exact same as the HO manifold I have out of the car. The passenger side I could not see the casting number but the output looks to be smaller and at a different angle. I only decided to cut off the Y-Pipe after I matched the manifolds casting number on the drivers side.

The car is a 92 T/A convertible TPI car that originally had a 305. I understand that these cars had the smaller non HO manifolds. The motor is out of a 90 Formula 350.

The plan for this summer is - HSR Intake, AFR Enforcer Heads, Summit 8802 cam, Headers of some sort, and finally a Fitech to do the management. The more research I have done it sounds like the stock manifolds and the edlebrock tes headers will not work with the exhaust ports on the afr heads. To spend money on getting a y pipe fabricated for them is pointless.

Honestly this was a frustration post. I had been working on the car for weeks. Did not need to do the y-pipe now but decided to anyway. Now I just need to clean up the mess. My biggest fear is I pull that manifold and break a stud. The good news is they have obviously been off before to be installed on the l98 when it was swapped in so the bolts don't have 30 years worth of heat and grime just 15.....lol

blacksunshine'91

iTrader: (10)

They're not as easy to find anymore as you'd think. They're getting really hard to find. They pop up from time to time, but they're not always available.

blacksunshine'91

iTrader: (10)

I had the same fear when I replaced my manifolds last month. Just hit the bolts with Knocker Loose (from CRC) a few times a few days before you want to work on it. Let that stuff soak in. Then just go slow and the bolts should come right out. Just remember to not force anything.

sublimed

Here is the ultimate punch line to this joke. I have been hitting them with penetrating lube the last few evenings. I went out to hit them again tonight. Decided to see if any thing would move. The first one was not even torqued. Neither was the second. They all basically just came out without a fight. I go over to the drivers side and it is missing three bolts/studs. The exhaust leaks were probably coming from the manifolds.

blacksunshine'91

iTrader: (10)

That's funny. Felt similar when I removed all my bolts. Was sweating the removal for weeks, not a single one of them gave me much hesitation at all. Make sure you use a thread chaser to clean the head bolt holes out before you reinstall the new bolts.

My issue is that tonight I went to install the Magnaflow y-pipe with the spacer on the passenger side, and the bolts on the passenger manifold aren't long enough to go over the spacer and through the y-pipe flange. So frustrating.

sublimed

Did you swap the manifold? I also noticed that the studs on some of the HO manifolds appear to be longer on top of the different exit points. I feel like we may both be dealing with 92 convertible issues. It is almost like they decided to change the y-pipe setup to clear the vert-reinforcements. My y-pipe looks similar to yours except on the passenger side it looked cut and rewelded.

Let me know how everything goes. I purchased the no name header/exhaust setup. I figured the worst thing that happens is I put it on the other car.

So now I have a Magnaflow y-pipe and manifolds I know were working with on another third gen.

Edelbrock emissions headers with a mangled Y-pipe.

Ebay stainless longtubes and an exhaust to go with them. Something is going to work. Just don't know what yet.....

blacksunshine'91

iTrader: (10)

Yes, I swapped manifolds. A previous owner had some crappy manifolds on there that had a 1 3/4" outlet, not the original LB9 manifolds. I installed the exhaust manifolds from the L98/HO engines. The Magnaflow y-pipe lines up perfectly with them. I tried to use a small crush metal gasket, but the pipe after the y was hitting the floor of the car. With the correct spacer, it gives me a solid gap between the pipe and the car, about the thickness of my fingers. If those studs on the manifold were just a pinch longer, everything would be golden.

I didn't want to go with headers on this car for a couple reasons. I have headers on my GTA. Yes, they flow much better, but headers come with their own issues. Plus, it's a 305 convertible. I'm not trying to race anyone. I wanted a simple cruiser that looks and sounds nice.

sublimed

This was also intended to be the cruiser for my wife. Now she stole the t-top car because it is "fun" and has working A/C. It has a 383 Vortec setup that was originally going to go in this car. The previous owner of the vert got in touch and informed me it had a really low mile l98 out of a formula. I didn't touch it after that and was working on fixing cosmetic stuff. Now I started to open the can of worms. Did the rebuilt transmission and full suspension overhaul. Have the subframe connectors to go on it. Was just going to swap out this Y-pipe and take it to the exhaust guy and have him put on the subframe connectors and fix the exhaust connection. That still may be the plan...lol

When I finished yanking the passenger side manifold tomorrow I will post the casting numbers for both. I'm curious if they match what you have.