Sunder you need to learn a bit more about the Jeep in question (74 CJ5).

First, it already has a fixed yoke on the rear output of the transfer case. All CJ's do.

Second, that old of a CJ already has ubolts in the driveshaft yokes. No straps to change out.

LadyFrog there are numerous, detailed write ups on the internet about spring over conversions. There are several tech articles here at www.jeepwire.com that you may find helpful. Go to www.google.com and search under "Spring over conversion", or "CJ spring over", or something along those lines. See what other people have had to do to properly and safely convert. Then determine if you and hubby have the skills to do it right. Spring over on a CJ5 with the stock narrow axles is not really a good idea. They are just so narrow that you lose what little stability you have. I highly suggest going with wider axles at the same time.

The best thing you can do is learn as much as possible about the pros and cons then make an educated desicion. These boards are helpful, but they tend to leave out lots of details. Too many who reply are merely regurgitating info they have read on the internet instead of first hand experience.

BTW, your problem isn't the spring under and ubolts. It's the little bitty 31's. Going spring over will do nothing if you stay with 31's. Grind the tips off the ubolts and get ubolt skids if they are that big of a problem. My CJ5 on 35s and spring under goes almost as many places as my spring over CJ on 38's goes.