Ive just installed new 15x7 & P215-65-R15/ on my 65 coupe! The rear axle is an inch longer on each end & my tire stuck out on rear about 1/2 in , if that much. I also
have air shocks 50 lbs in shocks too care of that. fronts ok.I really needed 4.5 backspacing. check your backspacing. I dont think 1,.in lowering in front will mater.
the rub point in front would be the lower front of fender & can be rolled back a little.18s will work fine depending on backspacing-Torque Thruch offers backspacing.
try this link for back spacing.
http://web.wt.net/~gilbert/backspacing.html
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