Wheel Size and Backspacing on a Lowered AD

[zimspad]

I have a 51 with a stock width Mustang II IFS and 2" dropped spindles. It is not bagged. I am ready to order wheels and would like to get it right the first time. I will be running a 15" wheel. Looks like a 215/70/15 with a 15x6 or 15x7 with 3 1/2" backspacing may work. What are you guys with this setup using?

[parkwood]

we put 15x7 with 3 1/2" b.s. on a '51 sub with air and have no problem. i'm wanting to say the tires were 215/60 15's.. let me check to make sure on tire size but think thats right..