The block casting code might help ID the engine. The location of this code is given above.
The Technical Specifications are contradictory.
The RPO225 235 Loadmaster engine was supposedly not available on trucks lower than 4000 series. Yet, as Rustednuts notes, the same Technical Specifications manual also shows an engine ID for a 3600/3800 235.
Regarding the full side cover, early 235s had full side covers, just like all 216s. However, I think that by 1950 the truck side cover was not full height.
The block (and the head) casting codes (and, date dating codes for head and block) would help to distinguish a 216 from a 235.
