[olddog]

The flow numbers look good, but you have to have enough displacement to use it. Ford's 427 FE wedge was able to hang with Chrysler's 426 Hemi back in the day, even though the Hemi had the advantage. If they would have increased the displacement to 500 CI under the same heads, the Hemi would have spanked the wedge.

That said I just do not see these heads doing much for a good 289, if at all. Even a 347 with good heads would gain very little, unless you reved it to the moon. I do think a Monster Windsor at 462 cid would make some serious power, if the bottom end is built to take some rpms.

I was surprised the exhaust valve was as small as it is, and the intake could have been bigger if they had wanted. Aren't these about the same size as a 4V Cleveland?