I used to always recommend greaseable u-joints as corrosion and lack of lubrication always seemed to be the cause of most u-joint failure.
I have found over time that the greaseable joints DO NOT work as well as non-greaseable ones. Especially a Spicer OEM unit.
The greaseable joints don't seal as well,and water and salt gets in,and the corrosion starts. I see it when we grease them,you can see the grease pushing the water out. Everytime youi grease them you expand and stretch the seals,and more water gets in. Most people also forget to lube them,which also shortens the life.
Non-greasable units have a much better seal,which tends to keep out water,and keep the grease in.
Look at most newer trucks. The original joints tend to last for many years. We replace them with greaseable ones,and they only last half as long.
I run a plowing biz in the winter,so we replace a lot of u-joints,or we used to. Since the switch to non-greaseable joints,we haven't replaced many at all.