I need some help with an old Dodge truck.

The lug will have an “L” for left, “R” for right hand thread. Driver’s side would have the L lugs, if they are at L and R.

Once again, talk to the guys in the Pilothouse Forum. A number of them have the larger trucks and will help you. The stock diff is going to be low geared and not easy to find parts for.

The most common MC fix is a Cherokee MC. The guys on the Pilothouse Forum have a template for a block that bolts to the bell housing and then the MC connects to it. If I remember, the MC rod will have to be lengthened

You’ve got “split rims…”. Have you ever changed tires on one - not fun, and dangerous as hell. Not many tire shops left that will service them. There are “non split” rims that work.

But as I said, you are working on problems others have solved. Talk to them, tell them what you are doing and you will get help.