The only 15's in current production that fit are made by Bogart. They're made to order. The only 17's are made by Greg Weld and are on backorder. I've only seen one car with them. Weld XP's are discontinued, but fit as well. Otherwise, you have to go completely custom. Greg Weld was working on some 15's, but with his death, who knows how long it will take for them to become available.
damn. i didn't really want to screw around with spacers or longer studs. especially because i'm not sure how that would work if i went with hub centric spacers.
you have a set of slicks on your set of original wheels right? i know i saw ona site ones that were perfect for the 2005-08 gts with 17s but i can't remember the site. it was a mustang site, i don't think it was a big popular thing like latemodelrestoration, or cjponyparts or american muscle.
For the stock 17's, Mickey Thompson 275/40/17 fits. It bulges a bit, but it fits, and that's what I run on my '07. I'm partial to M&H's, but unless you're running forced induction, they'll be too tall for you, so I would pick up the MT's. The part number is 3743R. That's the radial that you can drive on the street. They also make it in a bias ply, referred to as cheater slick. That part number is 3743, but I do not recommend driving that on the street at all.
yeah, i've got a spare set of bullitts, from a 2006, i bought them for my old car. i figure i can throw them on there and use them for track purposes only.
would you recommend either over the other for a track only tire? i don't know if i could fit two rims with tires in my trunk, so i'm thinking the radial may be better just so i could throw it on at my house, then drive to the track.
also would i have to put a set of sensors on the rim? i forget what they are called.
For what mods you've got, the 3743R Mickey Thompson will do just fine. Then you don't have to change the tires out at the track. There's people with a lot more power running those, so you'll be fine. If you don't put sensors in, you may get a dash light, but no big deal. I took mine out to the track last night and didn't get the message at all. Other times it'll pop up after just a couple of miles. I just change back to my street wheels and it goes away.