I've got new undersize main bearings for the pony motor on my 1942 D4 7J. The machine shop that I have regrinding the crankshaft has asked if I can determine what clearance is needed between shaft and bearing for lubrication purposes. Anyone know where I can find this spec? There's lots of manuals for the main engines, and for parts for the pony motor, but I'm having trouble finding service info. for the pony motor.