Hy nickcs2004, you didn't say what year truck you'll be transplanting the 57 283 into. The 55B and 56 trucks in Canada had 265s in them, 283s came in 57s. My 59 truck salesmans data book lists at least three different compression ratios, however the parts book lists only pistons with a different class of fit, and they only list one cylinder head for the Chev V8S, so how they come up with different compression ratios is a mystery to me.
