Good catch! I checked the paper Master catalog and it says the same than the EPC. So it seems the Toyota made an error in the FSM?
Where is located the date stamp on the transfer case?
1971-1974 Chassis FSM specifies that the transfer is 2.3 even on the 4 speed:
While the 1975 Chassis FSM specifies a different ratio:
On the EPC there are multiple references for both the 3-speed and 4-speed all along with PN change on 09/72, 09/73, 01/74, 01/75 and 04/75.... This isn't...
Transmission on a 74 is noisy. Mine also have a noise at some specific speeds (or probably engine rpm) but as long as it's working fine (and sound is not unbearable) I think you best course of action is to do nothing and enjoy your FJ40.