I was cruising thru an old thread on Vette 283's and came across a reply stating that "The 245hp engine was basically the 220hp power pack engine with dual quads instead of a single 4bbl. The 270hp engine had the Duntov cam, popup pistons, all centrifugal dual point distributor, and "single tower" heads instead of the "single pyramid" heads." What is the difference in the head types? Identifying marks or casting numbers?
Same valve sizes and port area, as far as I know. BIG difference in value, though. Going for the correct look? Grind the pyramids on a pair of power pack heads to resemble the single thin tower. Casting numbers can't be seen on a sbc when the valve covers are installed, anyway.
I havent checked my casting number yet but my heads have a triangle sitting atop a square boss. I saw a photo of the markings describing them as power pack heads. An "old timer" buddy of mine kept telling me that the pyramid was a real small marking on those heads....mine arent all that small to me. Btw this is a 283 in a 60 Impala. As far as we know its never been touched, and the family that bought it new sold it to us. I want to dress it as a corvette dual quad engine.
I've got both early and late (later?) sets of power pack heads, and your friend is correct--the pyramid on the '56-'58 vintage heads is noticably smaller than the pyramid on the '63-'67 heads. Are you going with stagger bolt or straight bolt valve covers?
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