Pinion angle shims:

DesertRat said
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.
Thanks for your input, Douglas:)

The confusion I'm seeing in the responses to your posts stems from the up/down relationship of your angles. The standard way of naming the relationship of "up or down" is in relationship to the driveshaft. You called the engine trans angle up, but your transmission should be referred to as 5 degrees down angle and the pinion would be referred to 3 degrees upward angle , as you have correctly stated.

That being said, it sounds like now your pinion angle is .5 degree down in relation to the engine trans shaft centerline angle. Nice.

I too had the poly locks, and did not like the vibration transmitted to the car through them. I called Schumacher and ordered their torque shaft kit and a fresh set of stock rubber mounts, I like this much better, but beware. They will lower the front of the motor slightly as they are thinner than the poly's. It is likely enough of a difference to change the centerline relationship between the engine trans and rearend. Double check once you have swapped them in.