[wooftfd]

will 64 716 heads, and tripower fit on a 65 421 block?

[johnta1]

Yes!

[Dick Boneske]

100%

[John V.]

wooftfd, if you are interested in knowing why they will fit, the explanation is that Pontiac revised the Intake Manifold bolt pattern for '65 so '65 heads were modified to accept the '65 Intakes. But the head to block bolt pattern was unchanged.

If you want to use '64 heads, they need to be matched to the Intake Manifold bolt pattern that was used thru '64.

So a '64 Tripower Intake Manifold will bolt to '63/'64 9770716 heads. And these '64 heads will bolt to a '65 block.

Another concern is the valvetrain oiling.

The 9770716 heads used the same pushrod oiling as all '65 heads, requires an oil hole in the rocker. But other '64 heads used the older style stud oiling, no oil hole in the rocker. '64 blocks had an oil passage that fed an oil passage in the head that would feed the rocker studs. The block passage was unused with the 9770716 heads. The '65 blocks won't have the block passage but no matter, it isn't needed with the 9770716 heads.

If I have stated a detail incorrectly, hopefully somebody will correct me. But if you're curious like me, I thought you might like to know why the 9770716 heads and a '64 Tripower Intake Manifold will bolt up to a '65 block, not just that it can be done.