Ok you wheel experts here is what I have:
Fronts: 17x9.5 with -13 offset 4.7" backspace. Rears: 17x11 with -13 offset 5.5" back space.
I want to re-barrel the wheels so I can have them fit under stock body lines. I know the easiest way is to sell what I have and buy new but I think I can save a few dollars doing it the other way. Plus I can sell the wider sections to someone here who wants to run big flares. Right now this setup currently work with the wider ZG flares I use to run on my 71 240z. I know I can get away with 17x8 or 17x 8.5 0 offset under stock lines. I am runninf coilovers on the new 74 260z so I am trying to figure should I measure the thickness of the mounting surface that would mate up with the wheel hub and calculate how wide I can go from there. What is "normal" backspacing on a 8 inch wheel with 0 offset?
I was using this calculator here:
http://www.rimsntires.com/specs.jsp