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Compression ratio question

June 17 2017 at 7:07 AM
ArnieO  (Login ArnieO)

I am building a 390 for a 67 cougar I have a set of C8AE-H heads that have been pocket ported and have CJ valves . My question is that with the gas of today would 10:1 pistons be to high with cast iron heads ? I don't want to have to add octane booster or kick the timing way back. It will be mostly a street machine , but would be run at the strip on occasion . the gears for the rear are as of yet undecided I found a set of 4:10s which is lower than I wanted but the price was right and that should be fun in a light car. Anyway I am figuring out if the power increase from 9:1 to 10:1 would worth it or if I'm looking for spark knock troubles . Thanks for all input in advance .....ArnieO

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