What backspacing on Bullit Wheels on a 65 stang???

Sounds similar to my wife's and my 66 coupe's. If you have that actually Bullitt wheels you'll need 1"(25mm) bolt on spacers for the front (unless someone makes a 7/8" set) and the same for the stock rear. Actually 3/4"(20mm) spacers would be better in the rear with the 245's. I just put the same thing on my 65 Falcon as well. Anyway, 4.75" backspacing seems to be the best fit.

i'm actually not using any spacers on the rear at all with my bullitt wheels and it works just fine...doesn't look bad either. I prefer to run without spacers if possible. For the fronts I run a 1" spacer..I had 245/45/17's on the front but they rubbed so bad it drove me nuts...i downsized to 225's and they work fine. Eventually I plan on taking 1" out of the front wheels so I don't have to run spacers at all