My son had a 360 built into a 408 last year, and against my suggestion, had the machine shop assemble it for him. Used RTV at Chinawalls instead of cork, and RTV around the back water ports in head (dead end at manifold, since T stat is at front) and it ran like ****. Couldnt adjust carb to save our life.... Got the Gumout spray out, bad vacuum leak by cyls 5-7 and 6-8. especially 6-8. I had him pull the intake and reseal it (engine has less than 2k miles on fresh build) and made sure he did it the right way (used cork end seals and no RTV around water ports) and that made a WORLD of difference. the only RTV was used where the cork gaskets meet the side gaskets at the head/block/manifold junction. Sealed right up, runs noticeably better. Mopars arent Chevys, RTV was a GM "cure all" from teh early 80s.... just because "it works on a Chevy" don't mean it works on a Mopar. I believe in minimal RTV. If I need a gasket holder or sealer, depending on where we are talking, I still use "Aviation" Permatex/"indian Head", or sometimes the yellow "gorilla snot" weatherstrip adhesive. Definitely makes it tough to get apart if there is a "next time" but doing things this way gives me alot less "next times" and I hate "redo's".