The Delco has an A circuit style field setup. the Ford likely has a B circuit system.
The A system is a field supplied by connections to the Armature terminal for power, (or a third brush near the Armature "hot" brush) the regulator grounds the field terminal, regulating the field strength.
The B system internally grounds the field windings, and the regulator provides voltage to vary the field strength.
The diagrams shown in the link are for IH tractors, and diagnostics for them. Later series, SM or SH will have regulators.
Google A circuit and B circuit generators to become familiar with the serious (let the smoke out) differences. Jim