4 link an pinion angle

[wraprail]

Tire size has nothing to do with pinion angle. You have to check the angle of the trans output shaft so you can't do it with the truck sitting on the ground. With the cab off you could. Anyway, whatever your trans tailshaft angle is (should be somewhere close to 3 degrees down) you want your pinion to be the same angle only angled up (opposite) somewhere close to 6 degrees total is ideal. This is at ride hight. If you set up your 4 link correctly this angle will change very little through the range of travel. I just did a triangulated 4 bar on my c10 and get 1 degree change.
Posted via Mobile Device
If you have an IPhone they have some very good angle finders in the app store for free. You can also pick one up at lowes. Check the trans from the end of the output shaft (remove driveshaft) and pinion you can use the flats on the yoke again with driveshaft removed.