I would sell the 8:71 to a BB Chevy guy and buy a new 10:71 for your motor
The bigger the blower the less RPM you need to turn it to make pressure, the higher you spin the blower the higher the inlet temps will get , IE a 8.71 making 7.0 lbs. of pressure may have a manifold inlet temps. of 180F +, the 10:71 making the same pressure at less blower RPM will have120 to 140 F inlet temps, which can make 50 to 100 HP more at the crankshaft differences. These are examples, not actual results due to the size of the motor, camshaft and induction system type (carbs, EFI, Bug catcher or whatever) feeding the blower differences