71 Dart Front Disc Conversion Questions

Yes, they should be small bolt pattern Kelsey-Hays discs on a 71. Yes, you use your upper and lower control arms. Have the calipers rebuilt by someone good. They are great brakes when in good shape. You can also get performance pads as well. The calipers bolt to the knuckle. Search the brake section and print some pictures so you can verify. Nothing like them, really.