[Michael C Henry]

My car came with mild steel pipes that had been wrapped with fiberglass heat tape.
there were so many cracks there was no start or stop welding point. I replaced the headers and side pipes twenty years ago . I had the same problem because the engine was not centered for weight distribution. My headers were header pipes bolted to a flange an then the four pipes all turned to exit the body and the collector and then the muffler and then finialy short turn out. I made a thick spacer where the headers met the collector, in side the engine bay. I used layers of thick copper I cut over sized plates to match the bolt together flange . I then aneled , stacked and filed the stack to make a solid gasket-spacer with 8 bolt and 4 exhaust holes. I had a way out. I have no idea of your side pipe configuration.