Whats a better choice (if there is) for a rear wheel rim size on a 67 mustang. 16 X 8 or 15 X 8? I'm looking to throw some 255's street slicks in the back. Would the 15" require a spacer? I know the 16's would. Thanks.

 

I don't know about spacers, but I am going with a 17X10 on the rear with 5.5" backspace. It should fit with little problems, may need to roll the fenders.

 

Not sure what your car is like, but keep in mind that when you get slicks your driveline has to be able to handle them...