Burd

What is typically used on the exhaust manifold to pipe, any gaskets or is it a flange fitting on the olds, a buddys doing the 403 in a TA.

joe_padavano

To be honest, I'm not completely sure on the T/A manifolds. It's easy enough to tell. If the manifold outlet has a metal tapered feature, no donut is used. If it has a flat surface with a counterbore, then one is used. The A-body cars did not use donuts. Other Olds cars did (my 67 Delta, for example, uses donuts).

olds 307 and 403

If the outlet is straight down, usually with 3 bolts, it requires a donut. Most of the 70's with catalytic converters and definitely all the 80's Olds V8 used this configuration.

Burd

Hey thanks. I’ll get A shot of the pipe or manifold and post it up.

69HO43

My source say it should originally have been a 563519 p/n for 403 T/A. That's a 3-bolt style with a donut, and spring loaded shank bolts. Unless they got some aftermarket style or something different.

leftlaneonly

I could use a donut

matt69olds

Burd

Thanks, I figured all Cop cars would use the donut. Lol.