Ron, the problem with AMC is, they changed the brake system details alot, the most important point is to GET EVERYTHING OFF THE SAME CAR - calipers, rotor, spindle, etc. If you're just trying to upgrade your car from drum to disc WITHOUT a donor car, you're in trouble, as you need the front hub spindle specifically for the disc brake system, it * may * not be the same as the drum. Don't get the calipers off one car, and the rotors off another. You * could * have problems, as the backspacing, etc. changed alot. Don't get the fulll-size Matador brakes, either, as the rotors have the bigger stud pattern. Stick with a Gremlin, Hornet, Concord, etc, get ALL the parts, including the master cylinder, and order parts for that year car. That's about the best you can hope for, other than finding the same year car as yours with everything, and doing the swap. Critical items are the spindle length, it MUST match the rotor and caliper, which is why you can't just buy the calipers and rotors and try to put them on your drum spindle. Other parts which are different from the drum system to the disc on the suspension are : Steering knuckle ( the bracket which attaches your hub to the drag link ), looks like an arm coming off the backing plate - there are 6 different ones depending on 6 or 8 cylinder, disc or drum brakes, wheel size, pad size, etc. and that's NOT counting the '77-78 system. So, if you're just trying to buy " off the shelf" parts, without knowing whether your spindle is the correct length, you could wind up with alot of parts you can't use. You almost HAVE to have a donor car, as you need the backing plate/caliper bracket anyway, which isn't sold in parts stores. Here's what my parts book "seems" to tell me : 75-76 are identical for hubs and discs. Calipers are same from 72-76. Hornet 75-76 is the same. steering knuckles between Hornet and Gremlin are the same for 72-77 years FOR DISC BRAKE SYSTEMS. So, that's all I can do for you, Ron. Hope this tech info hellps you some, but bottom line is you'll need a donor car for the special parts you can no longer get anywhere else. Also, you can USE other year cars, AS LONG AS you get ALL the parts off the car for the system, which may include different pitman/idler arms, etc. It should bolt onto your Gremlin, but you'll need it ALL. Good luck, Jerry in Virginia ( 8 Gremlins, 1 running...with disc brakes )