Coy's 17" Wheels 69 Dart

I have seen these on 65 cudas and 70 darts anyone know what size would fit 69 dart GTS Stock front small bolt disk and stock 8 3/4? I am think 17 x 7's with 4.25 BS. Could I get a bigger rear tire with 4.5 BS? What size tires?

http://www.coyswheel.com/coys.html