P30 chassis attachments to frame and spark plug wire issues

Sounds like leaking exhaust manifold causing wires to get hot. A large leaks are easy to detect by a clicking sound. Smaller leaks are harder to hear. I would get a piece of tubing and put it into you ear and go around the manifolds and listen for a hissing or clicking sound. After fixing mine with headers I bought Taylor wires that were 10.4 mm thick with fiberglass soxs on the ends from Summit Racing they were $170 but I have had the on since 2005 and are still good.