I bought the water pump spacer he mentioned but didn't need it when I mocked everything up.

I used Superformance gaskets everywhere, which are thicker than fel pro. That could be a difference or some other variable.

'68 Coronet 500 w/ Indy EZ-1 headed 446, 727 trans, 9" rear
First day at the track with SUV street tires and no traction: 1.688 60', 7.24 @ 101.79 in the 1/8 mile

Great customer service from: DominicThumper Carbs, B3 racing engines, Porter Racing Engines, A-1 torque converter's, Quick Performance, Racer Brown Cams, R&R Performance, Manton pushrods