Hi BrianI modified my SDU for reversal operation, including the oil pump. It's not just swapping the tubes, you also have to modify the internal pressure regulation valve.
Regarding the bearings; resulting axial forces of the helical gears are taken by symmetrical deep-groove ball bearings which are locked into place in both directions. I don't see any problems.
Have written more info on the OpenInverter forum: Tesla SDU oil pump modification for reverse operation - openinverter forum
Im having my project in the workshop mounting the engine. Will post some pics when I have it back. I have checked into the SDU and there are two quite thick bearingrings holding the bearings in place for any axial force in either directionGiving the amount of time that has passed since the initial post on this thread, I would love to get an update on it.