Chipmunk, go to Harbor Freight and get a angle finder. They are cheap and work pretty good.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=34214 http://www.speedwaymotors.com/xq/aspx/display_id.2916/qx/Product.htm If you have both axles out of the truck, set them upsidedown (spring perches up) on jack stands. Level the perches and read the angle of the pinion, then transver the data to the new axle! You will need the angle finder to get it right on.
I have read where you want the engine and pinion at the same degree of angle,(( example,engine down 1.5, pinion up 1.5)). Don't go over about 5 degree or you could get u-joint bind, somewhere in the 2 degree range is about right. Also you don't want a straigh joint, u-joints need angle to work correctly, the front one cancels out the rear one, each revolution the driveline speeds up and slows down each 1/2 turn due to the design of the joint. With one angle down and the other up, they cancel each other and it runs smooth, take away one angle, and you have a vibration, install to much angle, more vibration. Keep them with in 2.5 of each other and you are good to go.
Check out some four wheel drive sites and driveline sites, they both have good information on angles and joints.
Joe
