I have a set of rally's on my 65c10. 15x7 on the front and 15x8 on the back. All are 6 bolt. The 7" ones are quite rare. There are some out there. The rally's should fit your discs as they came out in 73 when most trucks had discs on the front.
You can buy reproduction rally's in most any size and width too.
Look on ebay. Or stockton Wheel.
