I'm way late on this but I'll throw a nod to Eric's piston pumps. I just skimmed so it might have been mentioned, but has the stock diaghram lp been ruled out as far as the oil diluting goes? If it takes a dump it will put fuel in the oil.
I've got a "factory" 6bt dual fuel filter head I need to put on mine. From everything I've read, it will clear everything and is straight bolt on.
If you wanted to try that route these are the parts & numbers you'd need:
The filter head I got off ebay is this number/variant http://www.truckhelp.com/parts/cummins-4989116 ............. or........... http://store.reliableindustries.com/eng ... el-filter/
Here's the same filter head but the Case part #'s http://www.minnpar.com/catalogdescripti ... TER%20HEAD
Stud- J925955
Nut- J903293
Small o-ring- J906695
Big o-ring- J906694
If you think you'd try that route I'll get the #'s off the filters I got for mine. To save a bunch (more) rambling, the filters I finally settled on were 13 micron absolute and 10 micron absolute.
PS: Donaldson gladly gives you the mic ratings for their filters, Fleetgaurd does not.