Your kidding right ? You dont have any traction helpers at all ,just stock springs and its planting the tires enough to run those #'s ? What are your 60' times ?
8 3/4 4.88 29.5 x 10.5W x 15 Slicks. I didn't run a adjustable pinion snubber until i noticed the axle was wrapping so hard on the launch that the axle housing actually had dented the shocks. The car was 60 ft in the 1.38-1.40 range. This was a 474 in a 72 Scamp.