yea ive done this on my 01 GT and 94GT with the stock brakes, and yes you must grind the caliper bar, but not all of it.
I had to grind more off the ends/edges, rather then the middle of the bar. I took about 1/4" off, or so.. not very much at all.. I wouldnt remove the bar all together, no need for that.
Just grind about 1/4" and see if that works, spray paint the caliber bar then throw the wheel on, tighten it down with 2 lugs, then spin the wheel, if it rubs it'l rub the paint off on that spot.then youve found the area that needs metal removed from.
my problem was the middle of the bar... thats had to be ground down mroe and beveled the bottom edge and a nice angle. then you can leavve alot of the bar.