Guys I'm working on a 1971 Cat D5 96J with either a 333C or 3306 engine?  Anyway my problem is I'm getting a good bit of fuel into the crankcase oil to the point oil no longer has viscosity and started blowing a fuel/oil mix out of the vent tube at high rpm so I shut it down.  Engine does not miss, crankcase blowby is very minimal, exhaust smoke was normal and oil pressure was actually still in safe range.  It was however extremely hard to get started the last couple times due to the pump loosing prime.  So do I start with rebuild on the injection pump alone or it and the lift/transfer pump?  

Start with inspecting/rebuilding the transfer pump.

1971 would still be a D333C with compact scroll pump and conventional transfer pump. Are you seeing fuel coming from the transfer pump tell-tale drain line (make sure the line is not plugged). Candidate fuel to oil leak sources are transfer pump seals, problems in the injection pump and over fueling injector capsules. The usual suspect fuel filter tower to injection pump seal would leak externally if the sealing was a problem.

Haven't had a chance to mess with it yet but it looks like a greasy mess around the transfer pump so it's very possible.  I'm hoping it's not my injection pump $$$ but not sure how much I trust it either though.  

  Done some investigating today. I'm gonna assume the pipe plug is not supposed to be on the bottom of the pump?

Your correct!!!!

I'm thinking that's the tell tale drain line connection that's meant to drain off any transfer pump seal leakage and yes it should be at the bottom of the pump but should have a drain line attached instead of a plug. With the drain plugged any seal leakage has no where to go except into the main engine sump.
 

Thank you all for the help. I now have a good place to start and yep it leaked fuel when I pulled the plug out. I really love running the little Cat she just needs a little work.