I set out to replace a sticking braker caliper on my GT Saturday, with one of 4 spares that came with my car. Much to my surprise they aren't an exact match. The spares that I have are physically larger. (longer and thicker) They'll bolt up to the spindle but take larger pads and the brake line connection is in a different location. I'm suspicious that these may be the infamous 1975 Manta calipers. How can I identify what I have?