Originally Posted by barnym17
The best way I have found is to increase the size till it revs cleanly in nuetral or park then go up one size to get in the ball park. The reason for going up one is more load in gear requiring more shot.
All of my Holley's out-of-the-box have always rev'd no problem in neutral - but my built motor needed several sizes larger on the discharge nozzle. You can't estimate trying to rev it in neutral. Big difference between in neutral and taking off on the street!