65 Barracuda Disc Brake Conversion Help Needed

Found out that the wheels actually have to be a 14x7" and have 4" of backspacing. Its the only one American Racing makes in the small bolt pattern. Would it make any difference if I went to a 14x6" wheel like a Rallye wheel with 4" of backspace? Thoughts? There are not many choices for wheels and unless I had some custom wheels made for the small bolt pattern (not happening) I don't know what else I could do to resolve this.

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