Finally did the shop vac into tail pipe/soapy water thing on my exhaust and came up with leaks at both connections to the muffler. Dropped the muffler and noticed that its flange mating surfaces were pretty flat, but that the header outlet flanges were not. A straight edge rocks about 1/16 - 1/8 of an inch across each flange in the middle between the 2 outlets on each side. Thought the gasket would seal the difference but it apparently doesn't.
So, is this normal or should all the flange surfaces be flat, and is grinding them down the easiest way to level them off?? Or can I put some type of high temp sealer on the flanges??
Paul