I'd be awfully suprised if the yoke on that ff14b is the same as the yoke on the 10b.
Also, I can't help ya on the u-joint. I got mine from a local driveline shop. I don't even recall the mfg of it. Spose I could go dig out the receipt to find out, if need be. However, I do recall ordering a NAPA ujoint and it wasn't what I needed so I had to send it back. I've probably got a reciept of that transaction as well. My point is, make sure you're getting the right ujoint if you're getting it from NAPA.
As for the spring plates - you can get by just slightly drilling out the 1/2ton plates to fit the 3/4ton ubolts, if you want.