That's what everybody pays attention to, but the whole of the cylinder with the head on is technically the chamber as well. Combustion occurs at the top, yes, but the whole cylinder is also a part of that. The LS valve thing is really interesting though.
The 3.8 60°V-6 around '04 had 8mm stems near the correct length, 1.89" int., 1.4-something exh. Wonder if They even checked into those, prob more $$$ even for stock ones.
