yyz1970

I have removed my passenger side exhaust manifold on my stock '72 350 to fix an exhaust leak at the Heat riser.
There is no sleeve in the pipe to center the donut...should there be?

My AIM on shows one on the drivers side?

Thanks for the help

0Willcox Corvette

There should be sleeve in both sides at the header pipe, and a flat gasket between the riser and the manifold.

yyz1970

thanks, I will see if the local muffler shop can make me one

therunningman2012

Hello all. I’m seeing the same issue. Today I put the car up on blocks to start looking at options for mine. Watching this thread for advice.

I’m faced with same dilemma. Should search the Internet for a spacer which I have yet to find for a 77 or replace the gasket and or donut as needed.

also something else I noticed this evening when I crawled under it. It looks to me as if the exhaust manifold has a few cracks in it. But I cannot tell if they go all the way through or not. It may be they are just on the outer edge.

Please look at attached pic and give advice.

thanks all.

7T1vette

Someone has put thick head-to-manifold gaskets in there...and then cranked the he!! out of the bolts to crack the casting. Not sure what issue they were trying to fix. With engine idling, see if there is any exhaust coming our of those cracks. If not, ignore them. If they actually leak exhaust, replace the exhaust manifold.
P.S. GM did not put gaskets under those cast iron manifolds. The heads and the manifold surfaces were flat enough to seal leakage.

bruiser

My 77 didn't have a donut or sleeve on the passenger side. New exhaust manifolds are cheap but getting the old one off can be a challenge with bolts snapping off.