WHEEL BACKSPACING AND OFFSET

[72mustang67gto]

Any suggestions on wheel backspacing and offset, I bought tire for my 72 convertible and waiting to order wheels to see what I want, tires are rear 255/50/17 and fronts are 255/40/17. im looking at the American racing wheels vn501 in the 9-9-1/2 wide rang, any suggestions on spacing? im trying to keep the tire just inside the fender wells enough that they will not rub, I don't think I will have that problem but you never know, the rear tires are 27" tall and the fronts are 25" tall.

 

[detritusmaximus]

One of these would help to make sure:

https://www.ebay.com/p/Percys-01201-Wheelrite-Wheel-and-Tire-Fitment-Tool-Measuring-Device-C6/621932976?iid=191958587730&chn=ps

 

[Don C]

A 9" wheel should have a backspacing of around 5".

I would search the forum to find out what wide rims others have successfully used.

 

[Bentworker]

That is a whole lot of wheel to put in the front of a 71-73.

Up front it depends a lot on your upper control arm. Most UCAs are only compatible with about 4.5-4.75" of backspacing using 17" wheels. In back with a 9" wheel I would go with 5 1/4" backspacing, or 5 3/4" with a 9 1/2" wheel.

Up front I would not consider a 9" or wider wheel. I have 17X 8.5" wheels with 4.75" backspacing and it just fits... With Maier UCAs I have about 3/8" clearance between the wheel lip and the UCA ball joint. On the outside I have enough clearance to actually turn and such with the coilovers set pretty low.