U Joint selection has me confused - 86 K10

[redneckwheelman2]

i would say forsure replace the ones in the front axle. kinda cheap insurance. since if they get to dried out and rusty they can split the axle shaft ear off. then youll need to get a new shaft and u joints. id recommend getting the spicer u joints for the front axle, there are not greasable but are sealed super well and built to last.
id wait on the driveshaft ujoints till they start to squeak or pull one of the caps off when you pull the driveshaft and see if the needles are rusty or not.

the driveshafts in my 87 have the sealed spicers which look to be originals and still have grease in them. the truck either has im guessing 189000 or 89000 miles on it. dont know if odometer has been rolled over yet.