Can someone give me an idea of what model Gravely's used that twin cyl. engine. I need one of those, any idea on the weight of that engine? I can already see it shoe horned in a bike.
This is just a thought, but an old 2 stroke has the advantage that they don't care whether they're upright, lying down or upside down so long as the carb works.
As for machining the Gravely for a drive side bearing, why do that, instead of mounting an outrigger bearing on the end of the shaft?
If you go back a bit on this thread and click on RicksRides name you can send him a P.M.
He has a vast knowledge of these motors and many others and can answer any questions you have.
From what I've seen just Goggling Gravely Tractor Twins they used Onan, Kohler and Vanguard V twins. Rick can tell you which one you should use.