I have the 94-95 design SLP headers w/ a custom dual cat exhaust. I have had these wires in for about two problem free years. I used the oem looms. When I installed them I used extreme care in routing and adding MSD wire insulation products and tie wrapped them in some places. It took hours to accomplish, but has paid dividends IMHO, much of the problem LT1 folks experience with burned wires, misses, etc is due to sloppy installation. One must install LT1 plug wires very carefully and ensure they are protected.