Randy 71

TOPIC says it all. I am going to get the exhaust done soon. QUESTION, I have 2 inch now. I am going to 2.5 inch. Correct me if I am wrong, All the manifolds from the mid 60's through the 70's were 2 inch? I beleive the only difference beetween the 2 and 2.5 was a pipe increaser from 2 - 2.5 at the manifold?


Thanks
Randy

Gordonm

If you are keeping the stock exhaust manifolds going to a 2 1/2 inch system will not do much. The LT1 exhaust was a 2 1/2 system wit h2 inch manifolds. The pipe of the manifold actually necked down slightly smaller than 2 inch then went out to 2 1/2 inch. If you are looking for a performance increase headers with a good 2 1/2 system will help a lot. I had headers with the stock 2 1/2 from the header on back. When I went to a custom bent 2 1/2 inch system with Flowmasters I picked up 2 tenths and 4 mph in the 1/4 mile. The stock pipes and mufflers are pretty restictive.
Here is a picture of my exhaust. You can see the H pipe in the middle. I do have a better picture of just the H pipe if you need it



[Modified by Gordonm, 7:29 PM 3/15/2004]

vettfixr

I agree. If you are just changing pipes you won't see much increase in performance. I went with Dynomax ceramacoat headers and had pipes fabbed to go from the headers to the crossmember with an H pipe under the trans. Here's a few pics. The stock mufflers were replaced in the last pic with Dynomax Ultraflow polished stainless muffler. They sound sweet.

norvalwilhelm

This is my old 3 inch exhuast showing the crossover right behind the transmission cross member.

71roadster

check my web site for pics.

Chris

Randy 71

71 Roadster,
I didn't see your web link in your profile.

mvftw

I went with 2 1/4" & a H-pipe. The exhaust pros said was the best combo for a stock Vette ('78)

Ryan77

I couldn't post a pic for you, so I e-mailed it to you instead :cheers:

joeveto

Go to my website. I have a full pictorial and description of what I did. It might help.

Let me say this: you'll never regret putting one on.