[Flathead Fever]

Some articles state 1 1/2 degrees and others say 2 to 3 degrees for a 9-inch or just about any modern type rearend. That means the u-joint is angled down 1 1/2 degrees coming out of the trans and then at the other end it should angle upward the same amount, 1 1/2 degrees. Figuring with a load on it driving, it will straighten out to just about zero, the bouncing up and down will cause enough movement to keep the needle bearings lubricated. You don't really want the angle set at zero degrees, because the needle bearings won't rotate in the grease and get lubricated, that why maybe 2 to 3 degrees might be better.

A flathead engine does not have much room to drop in the back before the intake hits the firewall if you're trying to straighten out the u-joints. Besides, I would think you want the intake sitting level, so the float bowls are level. It also depends on the length of the driveshaft. Look at some of the lifted jeeps with short driveshafts, they do terrible things to the angles of their u-joints. They'll work but for how long? You might not have the room (too short) to get the angle where it should be, you'll just have to get it as close as you can. Set the engine and trans in the pickup and load it up with some weight so it would be like it would be finished. Stick the rearend under it and see what you'll have for u-joint angles.