Generally, a 12" rotor fits inside a 16" wheel. But it depends on the caliper size, and the shape of the inside of the wheel, which is related to width and offset. I know that the Lincoln Mark 8 11.6" brakes looked pretty tight inside my stock wheels when I had those on for the winter.
Nothing for sure yet. I like my 35th Wheels and just curious as to what my options were. I'm definately looking at a set of dual piston calipers. Thanks
You're probably into a set of 93-up spindles if you want to go with dual-piston calipers. The stock 99-up Mustang (non-Cobra) calipers and brackets should bolt on the 93-up Bird spindles, using a 91-up T-Bird bearing hub and rotor. There is a tech. article on TCCoA about doing the dual-piston caliper on the stock sized rotors. And the calipers and brackets can usually be found fairly cheap. There are lots of Mustang guys who've put Cobra brakes on the 99-up V6 and GT cars, so take a look on Corral.net and similar sites in the classifieds for a good deal.
They might ... but what rotor / spindle combo were you thinking about ?? The Baer kit ? If that's the case, they usually have templates from their website available that can be used to check the shape and size of the inside of your wheels for the necessary clearance.