What is the correct backspacing for these wheels to bolt right on my 1984 B2000?

This

Or this

 

whats it going on?, if its a 2wd you will want the 4.50" bs or if you want them to stick out a bit or your putting them on a 4x4 go with the 3.75" bs

 

I think I am running 3 3/4 inch backspacing on my A/R's on the 87 B2000...

They came with the truck so I have really measured them yet, but they do hang outside the fender about an inch....



Hanging out a little....




Full right side view.....