Sidney004

While repairing a torn seal on a Grand Sport Caliper(J55 Style) I was able to accurately measure the race worn caliper and compare it against a used but street driven J55. The bottom dimension of the race worn caliper was 69mm across the flats. The top of the caliper(the unsupported "clamshell") was 70.5mm oriented toward the bottom of the car; 71mm oriented toward the top of the car. So this isn't folklore and most definitely occurs. Needless to say, I will be swapping in a J55 caliper with SS DRM pistons in its place.