Tubular Exhaust Manifolds

[brewmeister7]

Can I expect a power increase by swapping my '79 engines cast iron exhaust manifolds for a set of '83 tubulars?

 

[fc227]

Hello;

When I installed mine on my old setup . I actully lost a little ET , because it didn't spool up has quick , less velocity because of the bigger diameter tubes.

But it did help top end because they do flow better.

Downside, they crack alot about once a year I have to have welded up.


Gaskets , if the mating surface to the block is flat , use a little red RTV. I used to go though gaskets all the time . One time at the track I blew one , didn't have on to replace it , use Gray RTV becasue thats all I had on me . And it has held up for over 8 months now.

 

[b4black]

I've already got a cracked manifold on my 45,000 mile '83.

I'm probably going to swap them to the '79 manifolds. I considered aftermarket headers, but they are expensive.

 

[fc227]

Hey Rich;

Why don't you get them welded up. I know a few people up this way that can do it. I don't know how much , but drop me a Email , I can give you there Email address.


O yea , Are we going to get a spell check for this site ? , sorry to be a pain , But I really could use it.

 

[b4black]

I miss the spell check too. Unfortunately I don't think Jason will be putting it back. (I wish we could post pictures instead of just links as well. Ah, the good ol' days )


I probably will have them welded, but while they are off, I'll try the '79's, since I already have them. I want to see if the work with the '83 crossover and up-pipe (I think they will). If they do, this would be a cheap alternative for 84/85 and even the 86/87 driver's side. Maybe not the best performance, but they should be very reliable for daily driven cars.

There are only a couple of issues I can see. No O2 bung, but I think I can weld one in the up-pipe. And the EFE valve, which I will probably just remove the butterfly. The dipstick may also need to be changed.

I also may try the 81/82 manifolds which are very small. These might be great for spool up on a street driven car.

Here's the page with the manifold pictures:
http://www.flash.net/~rjgeorge/exhaust.htm

 

[Turbo-Rich]

Originally posted by b4black
I've already got a cracked manifold on my 45,000 mile '83.

I've got a cracked set on my '83 too
I bought a welded & strenthened set from Micheal McCoy
(M&M motorsports) for $180.
I've just about got everything settled in my new garage enough
that I'm about ready to start the swap.
Those back couple bolts on the pass. side look real FUN
to get too.
I have a few other things I want to do @ the same time.

 

[b4black]

Unbolt the downpipe from the turbo. Then you can push it aside. It's not that bad of a job.


The funny bolts with studs that the plenum brackets bolt to are still available from GM. I try to use new GM bolts since they are a locking bolt/washer. Regular bolts will loosen up. AND NO GASKETS, just some Permatex Ultra Copper.

 

[Turbo-Rich]

Originally posted by b4black

AND NO GASKETS, just some Permatex Ultra Copper.

Hey, that was gonna be my next question

Thanx for the tips