Pinion Angle Question

[chevy_mike]

Hi guys, I did a search and really did not find the answer I was looking for.

I am swapping in a '74 rear end into my '68. I have cut all the old brackets off the '74 axle and have ECE axle pads to weld on. I got the axle mounted to the trailing arms and the u-bolts snugged up. I got the housing centered from side to side. I had read you wanted 3-4* on the pinion angle. and got that set.

Before I welded these, I decided to check my old '68 housing. This is where I now am not sure. With the axle pads set at 0* (level) the pinion angle is pointed 12* Up. I also check with the pinion set at 0*, the axle pads point down 12* so I think my measurements are right (digtial leveler).

Should I setup the '74 housing to match the '68 measurements?

This in theory should keep things stock. Currently I have the axle pad set at 0* and the pinion is up 4*, which now doesn't seem right based on my '68 housing. I don't have the axle at ride height since I don't have the springs or panhard bar installed. I am putting 5" dropped springs but have no idea what ride height will end up since the bed is not on either.

Any ideas??? Thank.

[dwcsr]

It depends on if you have lower it or raised it. look at the link below, its the best info on prop angles

http://www.vibratesoftware.com/html_...aft_Angles.htm

[chevy_mike]

Thanks for the info. That's a good site. I actually know how to set a pinion angle but only with the suspension all setup and the car/truck sitting at ride height.

That's my problem, I don't have the suspension installed other then the trailing arms.

I went ahead and set the angle and welded the pads on based on my '68 housing. I was able to cycle the axle up and down, connected to the arms and at what "should" be ride height, it looked like the pinion was bout 4* and hitting the bump stops, about 1.4*. It looks like it did with the stock '68 housing so I think I am good but won't know for sure until it's back on the road.