Actually, the Saginaw M20 speedometer cable did actually go through the firewall where he stated. The Muncie M20 goes through where RickH stated. Remember, M20 is just a term for 4spd standard transmissions. Not all M20s are equal. The L30/M20 got the lower performance Sag 4spd when coupled with the L30 327/375 HP engine, and it's speedometer cable was longer and went through the firewall on the driver's side of the steering column, where as the Muncie's speedo cable went through on the passenger's side of the steering column.