914 wheels will they fit? Options

[brilliantrot]

I want to get a set of new wheels for my autocross car and have finally settled on Dimond steelies because they are cheap and not overly heavy (16pounds?). I am however wondering about what backspacing to order. I would like to run a 15x7 rim with 205-50-15 nitto NT-01's to stay in AP class because of the 100 tread wear rating. From what i understand a 15x7 with aproxamately a 5inch back spacing should fit but i just testfitted 15x7 cookie cutter rim with that tire from my dad's 912E to see if it looked like it would fit and it lookes really close. I am curently runing 195-55-15 yoko AVS ES 100's on American Racing 8 spoke vw rims (EMPI knock offs) and slightly rolled fenders with a finger withs clearence. My alignment in the back is 2.5 degrees negative camber and .07 toe out. I also have #140 springs on old Koni reds on full stiff if it makes a difference. Will i be able to fit these wheels or should i get 6.5s? Any advice would help because i would prefer not to pull the fenders anymore because the car was just painted and there is some bondo on the lower rear edge of driver the fender (fell off a jack PO). Fyi it is still a fourlug 1.9 on carbs with some other tweeks.