Combo 1- corrected flywheel hp - 911
(My memory is a little foggy, but i think this car may have actually gone 147mph)
Moroso hp for 3660/147 = 890

Combo 2- corrected flywheel hp - 652
Moroso hp for 3470/131 = 610

Combo 3- corrected flywheel hp - 705
Moroso hp for 4200/123 = 600

All built by me, all dynoed by me on the same dyno.
IMO, the dyno is a much more reliable way of determining engine output, as you can see from these examples, and my friends stocker, that some cars just make better use of the avalable power than others.