Later 261s were rated at 145 HP @4000 RPM. Maximum torque was @2000 RPM. Some of this difference may have been the marketing dept. leaning on engineering to run the engine up to speed to get the HP figures, but even the early 235s were HP rated at 3300. My 1-ton with original gearing would turn 3300 @ 60MPH. It got about 8MPG doing that but otherwise didn't complain. I now run the 261 in overdrive at 2500 at about 2" vacuum for hours on end and my only complaint is the gas mileage. If you hold RPM near the torque peak, the specific fuel consumption goes way way down. On mine a hotter cam with no other changes improved fuel consumption by about 30% @ 3,000RPM. So you can either turn it slower or use a hotter cam to get reasonable fuel consumption.
