I have a 65 Cuda I converted to discs up front using stock parts. I am running stock 15x7" cop car rims. Though to be honest I could pull the rims in more (increase backspacing) and have room for more tire.

The stock stuff increases the track about 3/4", I have no idea how much the Right Stuff kit might change the track.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.