Exhaust Pros/Cons for Slant 6
I used a fel pro exhaust flange gasket as a template to grind mine out, as it turns out when I lined up the mounting holes the 1-7/8 diameter hole that was the exhaust outlet was actually off center so I didn't have to touch it at one point but had to take the whole difference out on one side.... And it tapered down from there to the "thin point". I used longer burrs and tapered it in gradually as deeply as my carbide burr could reach.
And if you still have a leak, your flange on the pipe is probably warped