Short bed K10 driveshaft angles

[68isgreat]

I know driveshaft angles have been discussed before, but here's my dilemma:

I have a stock height 68 K10 shortbox stepside that had a 6 cyl/4sp from the factory. After installing a crate tbi 350 in the rear position, and a rebuilt 700r4/241c combo (which I know is a lot longer than the 6 cyl/4sp) and having a new rear driveshaft made, the shaft is only 38" long, resulting in a steep 16 degree driveshaft angle and 12 degree working angle at the xfer case (set at 4 degrees) and 9 degree working angle at the pinion (currently set at 7 degrees). If I drop the pinion down to 4 degrees to match the transfer case, I'll have a driveshaft angle in the neighborhood of 19 degrees and U joint working angles of about 15 degrees. Ouch. From what I've read, unless I want to be changing out u joints every few months due to the steep angles, I should probably raise my pinion up to point at the xfer case and go with a SYE and double cardan shaft, and drop another $1k down the rabbit hole. I should probably just call my truck a boat, short for "bite off another thousand."

What I don't understand is, how were these short bed K10's, and even the later OBS short bed trucks, set up from the factory and how did they avoid these steep angles? They didn't have double cardan rear shafts, or rear pinions angled up 15 degrees. An OBS truck (which came with the r4/241c combo) wheelbase is only 2" longer than my 68. I feel like I'm dealing with lifted truck issues, and my truck is only stock height. I must be missing something very basic here. Something doesn't add up???