A non full pressure is a dipper, babbit pounder, splashoil, low pressure, or non-insert (poured bearing) engine. Those are any 216 and the early low pressure 235. The later 235 was full pressure (insert bearings with drilled crank) but not full flow. Full flow means all the oil goes through the filter before it goes to the bearings. A bypass engine sends about 10% of the oil through the filter (if it exists) and back to the pan.
