X2 on grabbing another from your local junkyard/pick-n-pull.
I got a steering u-joint assembly WITH a rack and pinion unit I bought, all for $75 bucks from one of my local P-N-Ps. You can always check the u-joints for free play after you remove them from the wrecked truck. If they move freely then you should be good to go. In fact, I would recommend grabbing the R&P unit at the same time if they are both there. Usually the steering linkage gets yanked with the column or is at least removed or lost. The R&P in your truck will probably go sooner or later as well, plus, if you take a pickle fork with you and separate the tie rods ends from the front hubs, you will also have a couple of tie rod ends for future use as well. I poured power steering fluid into my R&P and cranked it back and forth by hand to (hopefully) keep the seals moist until I use it.