i installed long tube headers and a full flowmaster exhaust on my 86. i am very pleased with it. i have 1 problem, 3 tubes on the pass side are slip fit and 1 on the drivers. they are leaking where they go together (primaries come off the collector) the guy i got them off told me they seal when you tighten them down. but they dont seem to be sealing anyone else have this problem. help!!