Need Help Picking Backspacing

[slowk5]

I Putting a Dana 60 In The Blazer,Am Going To be Running 39x18x15 Boggers.I Have About 5.5" Of Lift.I Know I Want 15x12 Steel Wheels,I Just having trouble Picking the Right B/S.I Need To keep The Tires off the springs,And Dont Want To Spend All day Grinding The Calipers Down.Is There A happy Medium? What B/S Does Everyone Run,With the Same Set Up?I Was Thinking About 3.5" B/S Will The Tires Hit The Frame?

 

[b454rat]

I have the exact wheels/tires you have, and though mine is an 89 SAS, doesn't have alot of lift, and the tires didn't hit the frame, springs, or anything that i can see, other than the bumper and lower part of the fender. Not too many options when getting 15x12" 8 lug wheels. When I got mine, they said the only b/s space was 3.75. I have a set of 8s that I wanted to get widened, but for what it cost I could get a new set. Gringing the calipers down doesn't take that long, and for however long it does take it is well worth it. I have a few pics of the boggers on my truck in my sig....