What rear end are you useing? I think the Ford Exployer 8.8 rear-end I am useing is soposed to be around a inch narrower than the factory 8-1/4. My truck has 15x10 weld proatars with 5.5 BS and just eyeballing it, it looks like I shouldn't have a problem running a 4.5 BS wheel. Sense the class I was building my trick for went away, I am no longer stuck with a 28 inch tire. I might get a set of 15x10 with 4.5BS and some 315 pro-Bracket radials tires. I really like the looks of a deep dish wheel.