SHELBY GT 350 Member
Joined: Jan 2011
Location: Central Massachusetts
First, I think you need to be really clear about what wheels you have, how wide they are, and what offset they have. Maybe you are already clear on that; but I am not. I am not sure if your wheels are actually different front to back, or the same.
On the S197 cars, you could use the same wheel on all four corners and the offset would be correct. For example the GT500's came with 19x9.5 wheels front and back, all four wheels the same, with the same offset (not sure but I think it was 44mm), so they could be moved front to back with no issues. They were designed to clear the brakes in the front, and they fit on the back too.
On the GT500's, from the factory, they used 255 tires on the front and 285 on the rear. I have a set of those wheels, and I put 275's on all four, and they fit fine on my 2010.
Next, you want to size the tires to match the wheels. Generally for traction (on the back) you want the widest tires possible, without going too wide for the wheels. 275 is generally about the widest for a 9.5" wheel; 285 on a 10" wheel. If your current wheels are 9" or narrower, you probably want to think about new, wider wheels.
Next, think about -- why would you want to put a narrower tire on the front? Narrower tires will reduce steering effort a little and tramline a little less than wider, maybe hydroplane a little less . . . but if you have any road track duty in mind, you want the most rubber you can fit on the front as well as the back.
| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day