RH
If the alloy or if you wish no difference (stainless steel) could blow out then what about the head gasket? How can something trapped between two faces torqed down warp if its only mms thick it must naturally conform to the stronger items just because its never been done before dos not mean theres anything wrong with it or it cant be done my 928 crank was out of spec re thrust so i just had the bearing white metalled up to suit theres more ways of skinning a possun (of the downunder marsupial variety) than you think

Rich, What I was told was that for maybe 4x the cost of another set of Euro S heads you should be able to port US heads to flow as well. YMMV.

What I considered was to start with more of a clean design slate and use US heads and completely rework them with larger valves and modern port velocity porting. You hand your heads over to a good porter though, be ready to write a serious check. I'd say the guys racing 944's though pretty much understand the heads and what works.

I might be interested in your Euro S valves if you end up with an extra set. I might not know for a month or so though.

I agree Rich, but our friend down under sees things a little differently, and that's ok......

By the way, it's OPPOSSUM......at least that's what we have here in the States.

regards------