318 pistons

340demon said

why the limit of 9.5:1 built a teen-3 1 ton truck block with 68 flat top rv pistons and 340 j heads (63 ccs) and used felpro gaskets as i rember it figued out to about 9.6:1 used 88 oct reg gas back then now running it on 87 u/l crap with 8 degrees advance and 36 degrees total mach advance and about 15 degrees vac. advange with out and problems

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I want to limit comp as the cam will be small too, so no point in having higher than 9.5.Your 9.6 is close to what want tho.Musta had those heads shaved a fair bit to get 63 cc chambers.Also want to keep gas mileage decent so 9:1 ideally.


Leads to a machining question.Whats more cost effective at raising comp;shaving heads or decking a block?

Who made those pistons you used?Whats the comp height?Valve reliefs?