I bought a NOS moog pitman off of ebay a while back and it isn't provisioned for a grease fitting. I don't think drilling into the back cap to add one is a good idea; so my question is, should I just pack the boot full of grease and run it as is?

The mfr ing engineers must figure that if sealed the lube will be adequate forever which may or may not be true but I agree it goes against the grain to not be able to replenish the lube cuz that is what we do is change fluids. Same with Flaming Rivers' non greaseable manual steering box. I wouldn't be opposed to drilling/tapping for a zerk if drilled in the right spot as to not contact the ball and that I could get all the shavings out of there. If your old one is bad you could ecperiment with it & see what develops but engineers know what they are doing expecially on something as basic as this (lubrication) so I would as you said goop the amt of the ball showing and move it around then install the boot & slam it home