I have the Muncie 420 in my stock 1953 1/2 ton truck, and I have a 261 engine with torque tube and 4:11 rear gears. The granny-low first gear is about 7.1:1 ratio and un-useable in traffic. 5mph and the engine is screaming. It is only useful for pulling a heavy load, pulling the truck into the garage, or a parade. I use 2,3,4 for driving. And with the 4.11 rear end, 55mph is about top end and the motor is somewhat wound up. So I'm wondering if maybe a newer 4-speed (maybe the SM465) or T-5 might be of better use in your truck since you want a nice highway driver.
