Originally Posted by BOBCRMAN@aol.com
OK. The TRW pistons you have were designed to be used with rectangle port closed chamberGM heads
These heads are not the same in the combustion
chamber as the oval port. Tho, to the casual glance they look alike. The rectangle port heads use a chamber that is releived more around the perimiter. Making the chamber just a bit larger across the distance of the valve faces. The oval port head will hit the pistons on the exhaust side at the deck and outer edge of the dome.
What? I'm using TRW forged domed pistons with oval port, closed chamber heads in the 427 in my '71 Camaro. They've been in there for 13 yrs. now, and no clearance issues.
Is there something about these particular domed pistons the OP is using that is obvious that I can't see looking at them? They appear to be the same thing I've got in my engine.