Front disc / wheel / tire setup

So here is my plan, let me know if you guys think it will work.

Going with CPP's stock front disc brake conversion (stock height):
http://www.classicperform.com/Store/1962_67_Chevy_Nova/6874CBKS.htm

Going with American Racing Vector SE wheels:
15x7, 4" backspace, 5-4.75 circle (on all four)

I think I've got 215's on 14" wheels on the front and 225's on 14" wheels on the rear right now. I'm looking to keep stock width tires in the front...but how wide do you guys think I could fit in the rear? I'm not looking to do anything rediculous but do you think I could get away with 235's or 245's?

what year is the Nova? is it the 73?

Yep it's a 73, currently has drum brakes all around.

Anyone done discs on a 73 before?

yes you can do 235's or 245's out back.You need the correct bs out back too....not sure if thats gonna work with 4"bs out back.Post the same thread in the 3rd gen section...Those guys know their stuff!!bm