My thought was that the 71-74 B-body and 70-74 E-Body interchange. At least the 4spd pedals do. The 73-74 have slightly different brake pedal shape than the earlier ones but they bolt in and work in earlier cars and vice-versa. I have a 73 Cuda with an automatic and the dash and everything happen to be out of it at the moment. The main frame should be the same or compatible. I think it should bolt in for you but we'd need to do a little homework. PM me if you want and we can figure it out. There is a 73 charger in the shop that is a four speed and I can ask.