Hello, Bruce,

Post this question over on oldGMCtrucks.com

I have one GMC parts book through 1953 and another parts book for 1955 and later.

The earlier book shows your part number for 1953 GMC 350 (2 ton) with Hydra-Matic. That part number is not shown for 55 and later. You/we need a GMC parts book with Z-series (54/55) data.