26.4 diameter tire too big? 68 barracuda

I have 15x7 Cragars with 225/60/15 tires on the front of my 63 Valiant, and 65 and 67 Barracudas. The left front on the Valiant rubbed very slightly on hard left turns, fixed with an un-noticeable very minor trim of the lower front fender lip. Other two, no problems.

Relevant measures include not just tire diameter, or even just wheel width, but backspacing. The less backspacing, the more the outside of the wheel moves outward, and the more likely you will have clearance problems.