Thanks for everyone advice on romoving those exhaust studs. In the end, it was a combination of a lot of PB Blaster (like liquid wrench), a stud extractor (looks like a normal socket, but with spiral inners that grip onto the stud) and a propane torch. I did buy some freezer spray as well, but I think the torch never got things hot enough to take advantage of the spray. I ground down the manifolds to smooth the gasket surface. However the edges are rusted pretty good so I can't take them down without loosing a bunch of steel. Some areas around the exhaust holes have only about 1/4" of flat contact surface to the gasket. Is this okay? Next question, when putting the new studs back in, do I just hand tighten them and when I eventually put the manifold and nuts back on, will it set itself. Or should I double nut the studs and torque the studs in, remove the nuts, then put the manifold on then put the nuts back on? Finally, what torque do these studs need to be at. Thanks again, Pat vin5552