The enclosed page from the Chevrolet Factory Assembly Manual is dated July 23, 1955. It appears to be announcing the new full flow oil filter that attaches to the lower left rear side of the 265 V-8 engine block.
For the early 1955 year- after the introduction of their first small block V-8 – the oil filter had been a dealer installed by-pass unit attached to the front of the intake manifold. See tech article under 1955-66, then click on accessories.
As per the attached drawing, this new mid 1955 filter was not a spin-on design. The cartridge was inside a round housing that Chevrolet calls an “oil filter assembly”. One long center bolt was removed to replace the inner throw-away cartridge. This system was used on Chevrolet small block V-8 s for about 10 years while some other vehicle manufacturers used the spin-on filter as used today.