Quote: What kind of increase would you get if you just swapped to a set of factory iron heads with 40 cfm more and kept everything else the same?
Is this a test ???
Yes.
The 1971 cast crank 383 is bolted to the dyno. Someone has put on a 1969 4bbl cast intake. I believe this has 346 heads on it but we've never pulled the valve covers. Hopefully it still has the stock low compression cam, will know later today when we swap to the 915 heads.
