Unless the area you travel is flat as a pool table, the 216 won't be able to handle the higher gear on anything but flat or downhill runs. What RPM is the engine running at 50 MPH or so? I'm considering replacing the driveline-mounted water pump in my 61 GMC fire truck with a 3 speed Brownie, but the 401 V6 will have enough torque to pull the higher gear ratio without getting below the torque capabilities of the engine. There's a reason the COE has such a low ratio rear axle- - - -the 216 just can't make enough torque to pull a higher gear with the heavy frame and bed of the average COE truck. They were made for load-carrying capacity, not speed.
Jerry
