Kim: Following the GV manual I checked the front angle on the OD unit bottom pan. It read 5 degrees up toward the radiator. Then I checked the axle pinion angle using the GV manual instructions with a framing square off the rear cover bolt heads with the angle finder on the lower perpendicular of the framing square. It read 3 degrees up to the radiator as well. Per the GV book the 2 degree delta might have worked but they say ideal is within 1/2 degree. So I ordered some 1.5 degree pinion angel shims and installed them on the rear spring perches. Upon rechecking, the OD pan still read 5 degrees but the rear axle reading is now 4 1/2 degrees-should work. By your statement I need to go another degree change in the same direction to get the pinion lower than the GV angle. Thanks for the input, it is an easy change to make. I have test drove the car about 125 miles during testing and have verified the speedometer is within 1 MPH through the entire range and at 70 MPH my calculated RPM of 2400 is actually 2400 RPM with 3.73:1 ratio and 15" 275-60 tires on the rear. It appears I may have screwed the pooch by insisting on using PolyLoc motor mounts. May change back to stock rubber ones and tie the motor on the left side.