[Fot] Odd compression?

[Scott Janzen]

I had a similar experience with my GT6 a few years ago (though a different initial cause). Could be gasket or rings or a warped head, but for my car it was leaky valves that needed to be recut.  I had lapped them and my machinist had thought they looked fine too the first time when we resurfaced the head.   My first advice is to get a leakdown tester from Summit Racing or somewhere.  Pretty cheap and a great diagnostic device.  Especially with the manifolds off, you can readily identify the source of the leaks by the air whistling!  You'll probably have to run the test without your rocker assembly on, depending on how radical a cam you have.  The compression tester tells you that you have a problem - the leak down tester tells you where.

Payen gaskets are trouble free for me.  I'm guessing you are using stock head studs - with ARP if memory serves I'm torquing to 65 or 70 lbs.