I have a 67 Dart. The car was originally from L.A. and came with a slant 6. It now has a 340/4speed with 5 on 4 1/2" right hand thread studs on all 4 wheels. The front now has disc brakes and the rear has 10" X 2" drums on an 8 3/4 rear. The brake pedal sometimes goes to the floor when pumped. I...