Back in the day we all ran 15x12 , 8 lug bart wheels , eaton wheels and clement wheels that had 3 1/2 inch back space , on our 8 lug trucks. The reason why was you could get 15 inch tires cheaper and they were everywhere and we liked the look of a lot of side wall with little wheels , ( times have changed) . Anyway , what we would do is this ,
Grind the backing plates where the caliper bolts go through
Grind the top of the caliper itself
Go get the cheapo 1/8 or 1/4 inch spacers that slide over the wheel studs
Test fit wheel with spacer , grind until you have clearance all around
Then make sure you have long enough wheel studs with the spacer installed
That's it , let me add as well , our group of 4 wheeler's beat the crap out of our square's all the time with out a single problem. My crew cab , (mall queen) , still has that set up on it as we speak.
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