The gaskets I am using are some weird rubberized thing that came from Thorley. When I swapped engines several years ago, I re-used the same gaskets. They still looked the same as when they were installed. You can dig your nail into the surface and it feels soft, but I don't really know what it is or where to get them. I heard Thorley doesn't supply them any more. You may want to call Doug's Headers. Doug lost Thorley as a result of a divorce, and started Doug's Headers. The wires are some NAPA product. When I first installed the headers, I used the OEM heat shields. When I installed the 502, I switched to the sox. I've not had any problems, so maybe the issue is more the headers and free flowing exhaust. What kind of mufflers are you running? That can work against you, if they don't flow well. Makes the exhaust temps much higher.