I wouldn't run the 221424 with that cam, steel 2.3 valves, 1.7 rockers, at the rpm you like to turn the motor.

From what I've seen, the pac drag race springs often have noticeably more pressure than spec, even after they have been compressed a few times.
The 1247's I used the other day were around 340 @2.040 height.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads