This is what I use for my lubricants, from reading previous threads on the Ford Barn.
Recommended Engine Oil: Lucas Hot Rod & Classic 10 W40 oil – change every 1000 miles or once a year.
Transmission Oil: StalubeGear Oil 90SAE GL-4
Rear End Oil: Stalube Gear Oil 140SAE GL-4
Corn Head Grease for steering box: http://www.greenpartstore.com/John-Deere-Special-Purpose-Corn-Head-Gun-Grease-AN102562.html