Cletis- The 261 was offered in 1962 as an option on the 1/2 ton truck. The grease markings are still on the firewall of my truck "293" is the RPO (regular production option code) for the 261. Next to it is "4s" for the heavy duty 4-speed also installed. I also have the repro sales brochure stating the 261 available as an option. I know the 261 was only offered as a car engine in Canadian Pontiacs. Is there any way to tell if this 261 is from car or truck? Oh, I'm down in Lake Jackson.