Wayne,

7 degrees is too much negative pinion angle. If you are going to quote me, please post where I told you to run that much.

This isn't rocket science. Depending on the ride height and drivetrain angle of the car, setting pinion angle off the driveshaft is purely hit or miss.

For example, assume your race car's pinion angle is set perfectly and the car has no vibration.

If you raised the engine in the front 3 degrees, changing the drivetrain angle downward, the correct way to compensate for this would be to increase the pinion angle 3 degrees POSITIVE, because it keeps the pinion parallel to what you had before.

If you tried to set the pinion angle off the driveshaft alone, you would increase the pinion angle 3 degrees NEGATIVE, most likely causing a severe vibration because of U-joint binding.

BTW, this is also the correct method to set pinion angle on a lifted 4 x 4 truck with a 1 piece driveshaft:

1. Make the pinion parallel to the transmsission.
2. If pinion binds, lower transmission in the rear.
3. Reset pinion parallel to transmission.
4. If pinion still binds, install a CV joint on the transmission, and point the pinion directly toward the CV joint.