340 heads on 360?

crackedback said

Until the heads changed to magnums, they were all open chamber, IIRC. Even 308's were open.

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Nooooo, the late '80's-early '90's heads were fast-burn Heart-shaped chambers with a definite squish zone, which is why they could run stock small rollers w/ 9:1 comp.
on regular 87 octane................