(Question 1) I gave you in the (P.S.) post the nut that holds the Pitman arm is 1 5/8.
(Question 2) I am at work and cant check any of my reference books that I have at home. I am in the middle of moving so if I see you dont have an answer after I un-pack I will look it up for you.
(Question 3) There are grease fittings at the bottom of the pitman arm (under the part that moves like a joystick). The Idler arm has it on the same spot as the pitman arm. Now that I think about it, if what I said in the other post is true and 73 have the pitman and idler arm that blot from the top down they will both grease fitting will be on top opposite the (joystick).