Hard to about modifying the head since there's a lack of actual before and after dyno or road test results.
Patrick Dykes told me he's seen a few 235-261 engines on dynos over the years and no street engine makes more than about .7 hp per cubic inch even with extensive porting on a stock iron head.
Yesterday I cc'd the 848 head going on my 261.This head had a clean up mill of .008 and appeared to be never milled before.New exhaust valve seats and new stock style 1.5 inch Chevy V-8 valves and extended core spark plug,like a Champion Y type
The combustion chambers were 79 CC on average.So if this engine is zero decked,using available .050 compressed head gasket,the static compression ratio is 9.15.
