you tried to see if the headers are leaking? the BBK headers have a common issue with blow out, Mr. Gasket makes a copper gasket for 302 blocks I recommend getting those and a set of the Stage 8 Fasteners put some copper seal on the threads and tighten them down from the middle out (like a head or intake) this will ensure a proper seal. Also spray deodorant (powder type women's) will help to find the leak good luck!

you can get the gaskets from O'Reilly or Autozone they normally stock them and its a simple job... well kinda

hmm x-pipe leaking... jack it up put it on stands and see if you can find it... might even be the clutch

BBK exhaust products for Fox Bodies are notorious for bad fitament. after trying relentlessly to get the leak to stop at the ball socket I went back to my usual brand of exhaust MAC headers and h-pipe and have never had an issue with them on all of the different cars I have used them on.