Originally Posted by SamE30e
They're designed to use stock head gaskets... And at such low boost, it's un-likely that it would blow unless the engine was not previously maintained properly.
What you do is buy a M5x with good compression, do a refresh on all the gaskets (incl. the head gasket) and then swap it in. With all the gaskets/seals done, the bottom end should last longer than your shell would hold up