I just went thru this issue a few weeks ago. The passenger side gasket between the manifold and pipe was shot. When I got the gasket out, one side looked like someone had taken a bite out of it. When I order the new gasket from AB I also order the studs and nuts. I sprayed the crap out of the area with PB blaster and the nuts came off without a lot fuss.If you come at from below with a long extension ( like a 2ft from HFT) it is not too bad. It is a PITA to get the new gasket in place. I got it back together and smoke came out the nuts on each stud. I took those off and put brand new ones on with some thread lock. No leaks now and my D2 does not sound like a Sherman tank.

 

Sherman tank indeed! Thats how I'll describe it too.