Wheels and Tires

[Michael12]

I have a 70' chevy c-10 1/2 ton 2wd and I am dropping it with 2 1/2 spindles in front and 4" coils in the rear.
Now since I am not a tire guy, and feel like an idiot for not knowing exactly how the #'s effect the size of the tire and what not.
I have a free set of BFGoodrich tires i won in a raffel, I can either get All-Terrain T/A or Mud Terrain T/A I think the all terrain will look better on a dropped truck.
My question is what will fit and work? I know I need to be atleast a 15' wheel because of my disc brakes, and I was thinking of a wheel something cheaper like the Balk dayton's. The wheels need to be 5lug x 5"... so if i went with a 15" x 8" wheel would it first work and what size tire would i need?

Thanks for your help. Sorry I am just a youngster trying to learn from all you experts out here. I love what everyone has to say and what you all do, and we all have the same love with these beautiful trucks.