[FattyBoomBatty]

That's what I did. Stainless steel "safety" wire. Then a regular gasket. But I surpassed my old boost level (by one psi) and it held together, so in my mind it works. The true test will be 30psi. Also, I think it would be better to o-ring the block since it's probably easier to get the groove centered on the bore. With a head, the bore centers might be slightly different than the block or inconsistent from hole to hole.