Compression ratio what to do??

JKrebs said

I'm building a new 340 for my 68 GTS. I have a 340 from a 69 gts. Steel crank .030 over with silvolite 4 dimple pistons. I plan on using the .028 head gasket with X heads. Using Lunati 703 cam. I cc one on the head chambers and it came in at 74 cc. After running the calculations I come up with about 9:1. I want to be at 10:1. Question: would would you do, shave the heads or use different pistons to get to 10:1? Or should I care? The difference between 9:1 and 10:1 is negligible.

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If you want the compression ratio up, the piston need to be above the deck.

The difference between 9:1 and 10:1 is, as a percentage is greater than going from 13:1 to 14:1.
That said, I don't like running the CR that low. With the right cam (not a BIG cam but the RIGHT cam which most likely won't be on the shelf) and a proper tune up more CR is always better unless you do it by shrouding the valves with a bad chamber. An early closed chamber BBC head is a good example of a piss poor closed chamber head.