Going to buy spindles. Have a question

[Damon23]

I keep hearing about buy spindles according to the rotor size. I hear 1in and 1 1/2 inch. What am I measuring?

I am going to get 2 1/2 in drop spindles for the front and 2in shackles for the rear and call it done. I was also reading where I need to get spindles with the correct placement for the tie rod ends so they dont get into a bind. I did'nt quite understand that but maybe someone could chime in on that. Anything else I need to buy to go along with this?

My truck is a 82 short wheelbase two wheel drive that is sitting stock right now.