Backspacing on 15x8 on a 69 C10

[cobb_ben]

I am going to buy rims in 15x8 for my 1969 Chevy C10 SWB. What is the proper backspacing to use to clear on the front end, suspension, brakes, fenders, ect. I can get 2,3,4in backspacing. I am running front disc brakes off of a '71 and 11.75x.81 discs on the back. They are the stock car style rims, Basset wheels, I think, 15x8, 5x5, 2,3,4in backspacing. Also what size of tire should I run??
Thanks
Ben Cobb

[ShamrockCustoms]

With the wheels off, take a good straight edge or level. place this at the wheel mounting spot on the rotor. From the top of that straight edge, use a measuring tape to see what your distance from the straight edge is to the fenderwell. That will be your max backspace clearance. (Note: this does not take into effect the turning radius of the OD of your tire!, you must compensate for this or you will rub the tire on fenderwell.)

Then , you can also measure from the straight edge to the lip of the fender to get the outside clearance measurement. The total of both would be the max width wheel you could run, but again this does not take into account the turning radius. You must compensate for this. Make sure you have clearance! Good luck!