A few questions...
 

I just picked up an 05 GT and plan on replacing the wheels/tires and lowering it.

What is a nice size/offset rim and tire to go with that will fill the well nicely but still give no problems with rubbing? And do I go with a wider tire in the rear? And lastly.... whats a good drop to go with? 1.5"?

Thanks!

I've seen people with s197's pull off 20" rims all around with no real issues. but if you want it lowered i'd stick to 18's to make sure of no rubbing when cornering hard . someone else hear can tell u more than i can with that.

yes go wider in the rear! omg i love stangs with fat ass rubber in the back:chacha: someone more knowing can tell you safe sizes and if you need spacer's and what not.

as for drop.. i hear with the S197 the eibach springs are a great setup. i'd look up different reviews for different sets. roush, steeda, and FRPP are also good brands

good luck, and add pics if you decide on anything!:tup

I'm not a huge fan of anything that has anything bigger than 18'' rims, I know several of these guys have got their cars lowered and such, but how much exactly... I don't remem.

Let me help with this one. I went 275/40/18 all the way around, rims were 18x10 Roush chromed-no rubbing on Michelin pilots (expensive) and lowered it with Steeda springs approx 1 1/4 inch. Flowmaster exhaust 40's and a Steeda tri-ax short shifter. After all that I traded her in on a 500 which probabely was a good move. Time will tell. Hope this helps:chacha:

You can typically go with up to a 1.5" drop on 20's with no rubbing.
Anything beyond that and you may have issues.

You are looking for a staggered look with wider rear tires in the rear so most go with a 9 inch front rim and a 10 inch in the rear.
The typical offset for a 9 inch front is 30-35mm and for a 10 inch rear the offset is typically 45-50mm.

I have seen a 24mm offset on some wheels too but if you ever want to upgrade your brakes to a bigger caliper that will likely eliminate that option.

One thing to remember is that if you lower 1.5" and go with big meat out back you will need an adjustable panhard bar to straighten the axle. You will likely also need caster/camber plates to do an alignment.

The size of the rim 18's, 19's or 20's is simply a matter of opinion so go with what YOU like and don't let others dictate your tastes.