Another Wheel Question

[cubber]

Ok, so I have spent several days searching, and have learned a lot about wheel and tire fitment on these trucks. I have a 69 STEPSIDE on 72 suspension (front and rear) I will be installing air ride and McGaughy's 2.5" drop spindles. I have a brand new set of wheels and tires that I bought for a truck I sold, and would really like to use them. They are Ion Alloy 15x8's with BFG 255/70r15 radial tires. The wheel backspace is 3 and 7/16". Lolife showed me a pic of a SLICK blazer with 7" rallys, and the tires tucked the way I want mine to. I know the 7" rallys have 3 and 5/8" backspace. I guess this would mean that the outer edge was 1" farther out? I have driven my truck with a 2/4 static drop, and had no issues, but I wonder how the new spindles and bags will change the geometry, and if the wheels will tuck in the fenders so I can set it down. I cant measure because i am waiting on my Porter built front end kit an c notch before i do a mock-up. Just wondering if this wheel and tire combo could work, and if I will have to clearance anything. Sorry for writing a book, I just thought it would help to give all the info I have so far. Thanks soooo much.