Just a brief update. It took me almost three years to get off my wallet and buy an aftermarket air system from Old Air for the '66 C10 250 6 cylinder. I had the system charged last week and the air blows a cool 43 degrees. I worked a couple of months on the install following the detailed instructions from Old Air and adding an electric fan to the install. I must admit, the project stretched my mechanical abilities (you have all read my posts) . I did have help - in that John Price from Old Air answered my MANY questions - no matter how trivial - by email and on the phone. All in all - it was a fun project and I got to know my truck much better. I guess what I'm saying - if I can accomplish the install - almost anyone can. Tim-o