Does the exhaust gasket (donut) go outside or inside? Everything online shows the gasket as 2-1/32. It looks like there is old gasket material inside the pipe, just doesn’t seem like that would do any good.
The donut sits inside the bell of the pipe. Be sure its sitting square when you tighten it up. Tighten evenly, warm engine up, then check the nuts again. You also might try to wire brush the manifold sealing face if you can to clean it up. John
Yup, the cleaner and smoother the surfaces are the better. Some pipes have a sleeve pressed into the pipe that holds the gasket square and makes it easier to mount and get a good seal.
38 Chevy 1/2 ton being resto-moded 65 AC Cobra replica USAF vet