So I purchased a 1989 GT that has been lowered and has been converted to a 5 lug using axles and spindles from a SN95. The front has 13 inch brakes with a dual piston calipers. The back axle is a stock 8.8 with a disc brake upgrade and axles that are 3/4 inch wider (longer)on each side. It currently has SVE Saleen style 18 X 9 inch rims with a 6 inch back space that I've removed to sell. I'm also removing the lowering springs too include struts and going back to a normal ride height and adding a drag pack tire set up. For the front I know I need a 17 inch rim to clear the bigger rotors. However, I plan to run a 15 inch back rim with ET Street Bias tires. My question is regarding what size rim and tire setup to use keeping the back spacing in mind. I was thinking a 15 x 8 with a 6.250 back spacing, but I cant find anything that fits that specification. Any input on those running a similar setup? I'm trying to avoid purchasing what wont work. Thanks for any help!