The first 235 with full-pressure lubrication to all bearings, insert rod bearings, and aluminum pistons came in the 1953 passenger cars with Powerglide. The 1953 cars with the manual transmission and trucks with a 235 came with the spun babbitt rod bearings, low-pressure lubrication, and cast iron pistons, I believe that all of the 1953 235s had the 18-bolt heads. I know that the passenger car engines were 18 bolts, and the parts manual shows that the 235 truck engines were the same. The 1953 216s in trucks and the sedan delivery were the same as the previous 216s, with 15-bolt heats, spun babbitt rod bearings, cast iron pistons, etc.
Note that babbitt metal was still the bearing material in the precision-insert bearings in the high-pressure Powergide 235 engines
in the 1953 cars. . The babbitt metal in the low-pressure 235s was described as spun, or "centrifugally- cast," and bonded to the rod and cap.
