Drive the truck really slow up & down your street. If you hear any noises, you'll have to slide the Ujoint bell back and make sure the ujoint assy is still OK. If the Ujoint is OK, look forward at the tranny, or behind the ujoint at the T-tube or rear axle.
I've grenaded a few ujoints in my '54, but every time it was the 4 bolts that hold the ujoint together. Its weird that your ujoint would experience breakage failure at the splined part. If it happens again, you'll have to delve deeper to find the root cause.
Your problems could either be improper installation of the replacement parts, or a more serious problem we haven't thought of yet.
good luck
chip
