A rough guestimate of neutral line will be from the bottom center of the rear tire to the center of the camshaft at the front of the motor. It would be great to have at least one front adjustment hole below that line. I would start with a setting of one hole above the neutral line. Before final welding make sure you have enough adjustment to use all the holes. Box the housing brackets so they won't fold over (like mine did) if the vehicle gets out of shape. Invest in shocks consistant with the power you will have. I strongly advise going one step better than you think you will need. I am on my fourth upgrade in rear shocks . A bigblock and torqueflite make for a brutal starting line senario as power climbs.