There was a post on this forum describing a company which does a dry sump kit for the 617 (which also does not use the stock filter) just for such an application, This would be nice for steep angles too. As for just the filter housing adaptor, they do exist, my friend has one for a 617 swap into a Land Rover,some LandRover nut in CT made it custom. I'll see if I can get his info.
Happy trails, I'm doing some crazy wheelin' tomorrow in the Samurai, that VW diesel performs excellent in this thing, I just completely rebuilt the motor and installed it a couple of months ago.