My experience has been that U joints are fairly generic. Pull the old one out and take it to NAPA, or an "old" parts store. they will measure cap diameter and distance across the caps, and give you the correct one. If you want to measure yourself, do a quick internet search for universal joint dimensions.
https://www.currieenterprises.com/understanding-u-jointsAs with all of our trucks, you never know what was changed since new!
Jon
That’s what I did when I did mine. The kids at “O” or “Auto” will look at you like a pickle is growing from your forehead if you ask them to measure the U joint. But if there is a store in your town with an actual Parts guy....he will fix you up in no time.
On the other hand, if you are pretty confident that all your setup is original....then you will probably be fine with the LMC approach. I’ve had good luck with them as a supplier.