High-Pressure 235 engines were first used in Powerglide-equipped cars in 1953.
From 1954 onwards all car and truck 235 engines had a high-pressure oil lubrication system.
Using the term "Full-Pressure" can be confusing when reading a Shop Manual, because Chevrolet often called the earlier, low-pressure, oil-lubrication system a "Full-Pressure" system.
This is not to be confused with a full-flow oil-filter set-up, which was never used (from the factory) in a 235 engine but was used in 1958-1963 261 USA truck engines.
