Correct factory pinion angle

[realsteelGM]

Does anyone know the correct driveline and pinion angles for a 1967 gm fleetside with a two piece driveshaft? I will be swapping out a dana 44 housing and bolting up a 12 bolt housing.

[Wrenchbender Ret]

The rear end & engine need to be on the same plane, parallel to each other. 5 degrees max angle for the drive shaft with 1 degree minimum.

[geezer#99]

True, for a one piece they're parallel. For a two piece follow this link. Page 8 explains it.
http://www2.dana.com/pdf/J3311-1-DSSP.pdf

[TBONE1964]

Do you have or do you have access to an inclinometer?

Typically all GM cars from the factory have a 6 degrees engine/trans angle. This is referenced from a level floor which is at 0 degrees.

Every u joint needs to have a working angle. If the engine/trans is 6 degrees and the front piece of the drive shaft is 6 degrees and the rear piece of the drive shaft as well as the rear end pinion angle is 6 degrees, then you have no working angle at the u joints.

To determine working u-joint angles you need to measure the engine/trans angle and the first piece of the drive shaft angle. Let say for example the engine/trans angle is 6 degrees and the drive shaft angle is 4 degrees. The first u-joint (near the transmission) has a working u-joint angle of two degrees. I am not sure what the min and max working angles are for passenger car and truck u-joints are but 1 degree would be ideal.

It is important to remember that ride height changes the pinion angle and will also change the working angle of the rear u-joint.

I would shot for a rear pinion angle of 3 degrees with the truck on level ground and at the ride height you want. Also for minor changes, a shim can be used under the carrier bearing to change u-joint working angles.

[realsteelGM]

Thanks for you response guys, after taking measurements today, the trans angle is 6 degrees down, then the first drive shaft is 4 degrees down which is a 2 degree actual intersection. The second shaft is also 4 degrees down, and finally the differential pinion angle is 8 degrees down. This brings the pinion to a 4 degree intersection. The reason for asking, is that this axle could have been swapped out before I bought it and I'm looking for the correct factory angles.
The other factor is that the slip joint splines are badly worn and needing replacement. Would it be an advantage to putting a one piece driveshaft at this point.