An 850B runs a 6466A. I'd look at making a swap, as an engine out of a burn't combine or 4 row picker would be a cheap alternative. The 6619T in the 850 was only rated at 145 hp, which made it a fairly reliable powerplant, but a 466 is way more common. Tom
(PICS) JD 6619 engine oil pump gear won't clear crank journal...
