340 Piston to valve clearance w/RHS heads

On my 410 the pistons stuck out of the hole .016-.018 Just like yours. I am using RHS Heads from Brian at IMM. I have all forged internals with H Beam Rods. I used the SD Felpro gaskets that are .054 Compressed, 4.172 Bore. The reason I used the Felpro 519SD is I was gunna hit it with some NOS and at the time Cometic did not make gaskets for the RHS Heads. Now they do!

Quench was about .036. I have bounced this engine off 7200 RPM a few times. I usually shift it at 6500. Rev Chip is set at 6800 Rpm

The Fire Ring is a little wider on the SD gaskets. FYI

I always liked the headgasket to be able to fail before a piston when using nitrous, just for the reason that no matter how we all think we know everything, and how many things we check, sometimes we screw up and we pay the price in the biggest way.:iconbigg: