rally wheel size

A G70-14 is equivalent to a 225/70-14, I can't imagine why you would have had them rubbing the springs. It is going to be the back spacing of the rim that determines how close the tire is to the spring.

I have 255/60-15's with 4.5" of back spacing on my 68 Barracuda and have about 1/2" of clearance to the spring and over an 1" to the wheel well lip. The Duster and Cuda have the biggest wheel wells of the A-body cars.

BTW, I had 235/60-14's all the way around on 6" ralley's on my car before swaping to 15" wheels.