Jim Carter indicates that the smaller cam journals were used on 235s through 1954 (probably 1955 1st). That would conform to the use of 3835911 through 1955-1st as shown in the Master Parts Catalog (in the page-link given by Hoyt).
It is true the 911 block was used in 55 1st trucks, but there was a change mid year 54 from small journal to large journal cam. You can tell which cam you have by the width of the distributor drive gear. The small journal cam gear will be about 3/8" wide, and the large journal cam will have a 5/8" wide gear.
The GM parts book shows both large and small bearings for 54.
