If you can get reasonably good and repeatable launches, and the ET/mph repeats pretty well....... and know what it weighs......... you’ll have a good idea what it makes for power.
Of course....... that assumes everything works as it “should”.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads