Problem with 455 using w/z exhaust manifolds. I have always put the exhaust pipes up without a gasket and never had a problem. This time the left bank has a slight leak and I thought a doughnut gasket would help. The problem is I cant find one the right size. All the gaskets I have that came from 455 gasket sets have doughnuts that measure 2 3/8 " and larger at the metal flange that goes in the manifold. Felpro 60241 says its 2 1/8 but actually is
2 3/8". Fel pro tech line gave me # 60360 that is 2 1/8 ID, I need 2 1/8 OD.

Anybody out there know a part # or have any thoughts on this

Thanks,

Jim

 

The Olds W/Z manifolds do not use donut gaskets. A trumpet flange formed by an exhaust shop seals to the manifold without a gasket of any kind. If the angle of the pipe is wrong and the trumpet flange is to small you will get a exhaust leak

 

Thanks for the reply.

What you describe is what I have allways done. I have had these pipes on and off at least 6 times since I finished this car. As I said this time for some reason I have a slight leak only on the left side and thought a gasket might help.

Thanks again

Jim

 

I had the same problem and didn't want to take them off so I used some muffler cement on them when I put them together......Fixed the leak