my 72 blazer is equiped with a rebuilt 350 engine that has less than 7,000 miles on it. when i bought it, it had an exhaust leak coming from the headers, where they bolt onto the engine. when i took the headers off, the gaskets were thrashed. i replaced them with Mr. Gasket's premium gaskets. this solved the problem...for about a week. now they sound the same, and it sounds like its just getting worse. they are hooker headers and they are pretty old, judging by the rust and and caked on dirt. is there anything i can do to salvage these? if not, what would be the best headers for the money?