According to my D2 5U parts book there are two filters listed. The filter element for earlier tractors (up to mid 1951) is part no. 4A332 and the later, full-flow system element is Cat part no. 9F6700. Hopefully someone can help pinpoint the year of manufacture for the D311 in your crane.
take it out and compare it with a NAPA 1161. That is the full flow filter.
Thanks for the help, the crane is 2.5 hrs away, was hoping to make an educated guess before I get there π