Kevin -

No, I haven't measured any gaskets other than the OE composition gasket - it's right at .050", even after it's been torqued down with ARP head studs. There might be another gasket that's thicker, but I don't want to experiment with that, since the OE gasket does such a nice job of sealing - even with a little boost.

I don't really want to grind the chambers by hand for fear of changing the flame direction. It could be done by machine, but I don't want to spend time looking for a machinist who is comfortable doing it and I'm not anxious to spend the money for it.

Same on the pistons - they're already in the block and I'm taking so long to build this engine already, I don't want to back up - or spend the money to put more dish in them.

Current clearance at .037" is more than I had on the last engine at .032" IIRC, so .020" more would give me .057", admittedly a lot.... and maybe questionable. The flip side is the circular piston dish on the Wisecos that negates any available OE-designed squish except at the outer 1/4" of the piston.

The combustion chamber grooves are sort of a whacky idea and go against everything I've learned, but there do seem to be some positive results reported from some of the experimenters. I saw some pictures of combustion chambers that appeared to be getting excellent burn patterns, but some others that didn't look so good. It seems to matter how and where you cut the grooves, so I should probably try that as a last resort. It sure is an interesting idea, though.

I couldn't get the Diamante cams to roll far enough forward with the Chevy eccentric bushings, so I'm going to go back to the Montero cams and try the .020" head shims first to see what happens. One thing I considered was that with the Diamante cams being retarded and running a little more overlap, I might not have been seeing as much boost pressure as I might get with the intake closing sooner and less overlap. So, I might get even more dynamic cylinder pressure than just what is suggested by the mathematical calculation models.

I guess the old "build it, run it and see what happens" is still the rule..... but I'll sneak up on it. Next time (if there is one) I'll have the pistons cut with 2cc more dish.

I have a Gen1 Montero in the yard that I could take the heads from and check the combustion chambers, but that would cost more time and money. I had planned to use the cams from that engine, so I guess I'll pull the heads as well and save them for "just-in-case".

Frank