Originally Posted by ukoldschool
I think the easiest upgrade for you would be to get a pair of second hand GTA 305mm calipers from ebay......
to check if they fill fit Id advise you buy a copy of the parts CD. Im fairly sure that the hub for the GT and GTA is the same
The caliper does not bolt to the hub, it bolts to the suspension upright.
You will also need a pair of GTA suspension uprights in order to fit the GTA Brembo calipers.