The best sealer I have found for the exhaust bolt holes is from Toyota. It is a good high temp sealer. Works way better than any thing mopar came up with that I have seen. I was turned on to it by a transmission shop here. He had a bunch of tubes of the mopar sealer he said I could just have if I wanted. He wouldn't use the stuff any more. Comes in a good sized tube so you have plenty for other applications. part number is 00295-01281 if you are interested.