94 cutlass supreme 3.1.no start

i recently put head gaskets on a 3.1 because they were blown. sent the heads to a machine shop to get checked out and they were warped. they milled .010" off of it. when i put it back together it would not start. it as spark and fuel but i don't think it has any compression. i think the valves are not seating all the way cause the heads were decked. what is the best way to fix this problem


thank you