I believe the road draft tube for the 1940 engine had a removable cap at the top for adding oil. If you use that tube, you'll also need to install a valve cover with an oil fill cap on it from a later model engine.

Drop me a PM- - - -I might be able to help with the correct draft tube.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!