what is the differenc ebetween the two? a friend of mine is suppose to find some chap itr brakes but he told me there were 2 sizes...? he said there is a standard calipers and the big brake kit which is oem optional for the itr? is this right cause i never haerd of itr's having optional big brakes? What should i be looking into to get the itr caliper change on a 99 ls.