The 261 wasn't available until you got into the 2 ton trucks, in which case it was the standard engine. 1/2 through 1 1/2 ton used the 235.
Thirdcoast, you're pretty much on target, though it really can be broken down more. In the case of the 216/235/261, those can be broken down into 3 different series of engines, Low Pressure (216 and earlt 235), High Pressure/High Water Pump ('53 PG 235, '54 235 and 261), and High Pressure/Low Water pump ('55-'62 235/261).
Last edited by cletis; 02/03/2011 1:48 AM. Reason: corrected typo
