When I stepped down from a 17" rear wheel to a 16" on my Ram 1500, I also had to space the wheel out 3/4" and install longer studs. Even with some pretty vigorous grinding on the caliper, a 1/2" spacer just wasn't enough. I was compensating for a torque converter clutch that just refused to stay engaged unless I was running 75 MPH or so. Every time I'd tip in on the throttle, the converter clutch would disengage.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!