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Discussion Starter #1
He has flat top pistons,zero decked with fly cuts. This is a 350 that he just bought,and he has already bolted up a pair of 58cc heads to it.
I know this is a Ford site, and I love it,but I'm thinking his CR is going to be too high.
Does anyone know aprox. what this CR will be? He has a 2500 stall 4.11 gears in a short box.
I have learned lots from this site,but people just don't seem to believe what is right and what is wrong.
Anyways I'm just looking for a CR rate,then I will tell him he needs to pick a cam for it.
Thanks Steve
 

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I would say about 10:3 to 10:5.1 Compression.

Summit Racing shows a flat top piston with a 64cc head is 9:72.1 compression.I think a 5cc difference in chamber size is roughly a 1/2 a point difference in compression.So i would say 10.3 to 10.5 would be in the ballpark but that is my 2 cents i could be wrong though.

Later Mark.
 

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I ran that combo years ago in a class restrict to pump gas.Busted a piston firist night out.
 

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Discussion Starter #4
Thanks Mark. I supose he might get away with up too 10.5 but would still want to have the proper camming.
RCJ, sorry to hear that. My buddy says he's just gonna put the motor together and see what happens. I was just trying to give him some heads up.
Thanks Steve
 
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