[KrAzEcJ]

I cant be sure but those look like the 1230 series "soft rubber-fiber base" ones without a steel core reinforcement so race builders can trim material for a custom port opening. The 1230 is only supposed to be used on a race engine that gets disassembled on a regular basis. It wasn't designed to withstand longterm daily street usage. Again, I could be wrong on what type your using but I don't see any metal showing in the gasket where it failed between ports.