Ok as for the joints and installing the zerk that won't work...
The joints that are sealed are very well designed and in light use (not what we usually use our trucks for) will see 100k pretty easy, otherwise they might see 60k.
The spicers and aam versions are only cavity drilled about 3/8 to 7/16" that is usually enough grease to keep them supplied for a good long time under non towing conditions..
Light towing, or what i call "you're spoiling that truck" would be anything under 4500# should get 100k... But im no fan of the aam stuff, there joints aren't cold forged like spicers, and they play with the series sizes just a little so you can't use the spicer (this is for the people not in the know). The axle joints are a different story, the u-joints you need to find a spicer driveline shop and order the clips that are machined to different specs to use the better spicer joints in the shafts... if you can't find them, i can get them for you, or you can slightly remove a little thickness, slightly..
Now technically being in the driveline shop and towing for years..i think the 1480 series is overkill for us.. but it can't hurt.
I have a 85, 90 and 99.. I like the 85 the most do to the real crew cab..
It's a modified gas motor and using 1350 series made by me shafts upgraded from the factory then detroit 7290 design..
This truck pulls 10k to 20k without any issues for a long long time.. i just bought a 08 MC and im wondering if the springs are up to the work my 85 does.
OK onto your other questions...
Now when you put the little groove in... Make sure it has no burrs to rip up the glidecoat, make sure your dremel can reach in to where you put the zerk.
The alum shafts are great, i love alum, i have been making alum shafts for cars, trucks and even losing the 2 pc steels for a 1 piece alum shaft for many years now.
My customers that had a 2 pc and had a bad stub and slip i replace the entire assembly with a 1 pc alum shaft and they are in love with there truck all over again, when you lose 40 to 70 lbs in the driveline and replace it with 12 lbs...it's damn close to having a tuner installed...especially the gas trucks.
The down points of alum.... If you stick junk joints in the shaft that aren't coated.. you are going to experience a $$$ Expensive lesson... If for some reason you can not get coated joints, do not use them and order them... and don't let some other driveline shop tell you... ah you don't need them. they won't ruin the shaft right away, it'll take a little while, but the end result will be the same..
Now the front shaft would last forever if they offered the front hubs, and i think there is only one company making a conversion kit for them and it's fairly pricey