I am looking at 18-8.5 with 6.6 inches of backspacing. Is this too much backspacing for 1989 4wheeldrive and if so what is the most backspacing i can get

 

Holy Hell batman!!! Thats alot of Backspacing.

 

Stock 4X4 is very close to 6" backspacing, and stock wheels are 7" wide. With an 8.5" wheel, the 6.6" of backspacing serves to keep the outside edge of the tire closer to the fender. You will most likely still stick out past the fender, but not as much as if you had 5" or 6" of backspacing. Your wheel is 1.5" wider but you have .6" more backspacing than stock. Unless I am calculating this wrong, your tire will stick out .9" past the fender. Depending on your desired results, this may work for you. If you're trying to stay close to stock, just a bigger rim (18 vs. 15) I would try and find an 8" wide rim instead with the same backspacing. If you want the wider stance look, you can go with the setup you've found, or get n 8.5" wide wheel with an even 6" backspacing. I would stay within an inch of stock backspacing for fear of encountering rubbing issues, whether it be against the fender or against the frame.

Hope this helps!

 

thats not really that bad

 

Oh I know ours is 6 in but you don't normally see something with more than ours(at least I don't anyway) usually you hear of people that can't find more than 4-5 in of backspacing. I guess anything is possible. HAHA