I was looking at getting the American Racing Torq-Thrust M for my 69 Mustang in the 17 x 9 size, 6" backspacing and outfitting them with either 275 or 285/40/17s Goodyear F1 GS-D3s on the rear axle. The axle will be outfitted with the Baer Track disc brakes (on order), the fender lip rolled, and a spacer to push the rim out a bit (I know that 6" backspacing is a little much). Onto the question: What is the ideal tire width to fit a 17x9" rim? I was trying to look at the ETRTO and TRA standards to see what they say the ideal size is, but they want people to buy the standard. Thanks much in advance. Oh, if you know the sizes I'm looking at is a crap setup or will take much more work than I've let on, let me know!