[argonaut]

The rear wont be an issue because you are most likely running a single joint at each end. The offset provided by the lift springs will not affect relative angles much. The operating angle of the ujoints will be higher which means they wont live quite as long, but as long as they dont bind on full suspension droop you will be okay. If you do a shackle flip, then you'll end up rotating the axle.

In a 72 the front already uses a double joint at the transfer case. For this geometry the front pinion should point almost in line with the front drivshaft. So when you lift the front 4 inches it will mess up your pinion angle. You won't really know how much until you do it. On mine I was able to get away with a 4 degree shim up front to reach a compromise between the pinion angle and the caster angle.
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