If you are asking: "are GT right and left front calipers different?", yes they are. I just had mine re-built so they are sitting here on my floor. The castings are the same, but the rear halves (which bolts to the hub carrier) are drilled differently, right versus left. The bleeder valve should be at the top when the caliper is installed, with the female threaded hose connection at the bottom on the GT. With the calipers lying down on the floor, looking at them from the "back" with the mounting bolts down and horizontal, the left caliper has the bleeder in the top right corner and the hose connection is drilled in the bottom left corner. The right caliper is opposite (bleeder in the top left corner, hose connection in the bottom right).
If you have what Bob thinks (a Manta caliper), then both the bleeder and fluid inlet will be at the same end. This could work, if you actually have a "right-hand" Manta caliper, and you could re-route the brake lines. BUT, you CANNOT use a right-hand GT or Manta caliper on the left side, because it will cause the bleeder to be at the bottom, and you will never get all of the air out when you bleed the brakes. HTH.
