So theres no way to lift the tailshaft up any? I had mine at 0 & plenty of lift before it hit the floor, I like setting tailshaft at 0 & then drop the pinion 3* down for -3*, I had mine this way & no vibration that i could tell.

75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU