73-74 heads

I got a pair (casting # 1241860) 73-74 heads and found out the 70 intake does not match up. Thats OK, I would get a different (AL) intake anyway, but whats the status on the compression ratio of these heads? I threw a pair of '76 heads away, I know about them! Thanks

 

http://www.atlantabuick.com/CastingNumbers.htm

Try this link for info.

Mac Meece
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87 Turbo_T white pearl
84 S_15 500 cadillac powered
83 T-Type soon to have a 455 BBB

 

67-70 have 69 cc chambers, 71-74 have 71 cc. thats about a .2 difference in commpression.

 

I personally "cc ed" a set of 72 stockers and checked them 3 times in 3 different holes,and came up with 73 cc s each time. Stock valves, original grind, no resurface. Margin of error (+,-) 1/2cc