Big Block Heads ?

Bunz-T said:

Could someone give me some info on these big block heads. 3964290/3964280 E 11 70 They are on a 454 in a car I just bought with receipts for $750. I know they were cast may 70 but just wanted the good,bad, or ugly. Thanx

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I'd argue they are among the best in closed chamber oval port heads. With 2.19/1.88" valves, minor pocket porting, and valve unshrouding in the chambers, these heads can really shine. I had a pair and after I had them all said and done the chambers were actually in the 109-110cc range, but still way less than 119-122cc of open chamber heads. Plus closed chamber heads have the added advantage of more quench area.

hotrodmanIII said:

my speed pro book said there 97.4 cc's

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I've had more than a few bone-stock sets and none of them measured any less than 105cc. None of the catalogs or casting books I have seen have any actual test numbers for Mark IV BBC heads. They are all just going by what GM published when the heads were produced or what someone else has said.