Gt rotors on St, Will I need new calipers? Options

[Jeremy1210]

I want to buy the slotted rotors that are for sale on ebay, but they say they are for Gt. I thnik I have read that the GT rotors are bigger,if that is true, will I need new calipers?

[97GTinKC]

Are the pads the same for GT and ST? if not, then the calipers are probably different too. and if you dont swap the rear to GT disks, you risk changing the braking balance, could actually hurt braking performance, especially if you have ABS (did ST's have an ABS option?)... If I were doing it, I would try to get ALL the brake components off a GT, front and rear, including the proportioning valve, or at least spend some time researching part numbers to see what is different and swapping all affected parts as a set. (Or it may work great, anyone already tried all the different combos? )
I'm thinking that with the larger GT rotors, (they ARE larger aren't they?), even if the caliper is the same, the braking surface will be moving faster at the same speed, being farther out from center, this has to effect the stopping power differently, may not be enough to make a difference. there may be other factors i'm not aware of that will help compensate.
I have been this route on other cars, swapping larger brakes at the rear and not the front, and had problems with the brakes trying to lock up at one end b4 the other since I had upset the balance between front/rear.
It was great for making right-angle turns, didnt need to use the emergency at all, just cock the wheel in the direction you wanted to go, hit the brakes, the rear would lock up, sending you into a skid. then let off and floor it at the right time! but it sucked in the snow bigtime.