Truck Repair: fuel on top of pistons, cam shaft, exhaust port

Question
Several weeks ago I replaced 3 and 4 cylinder with a liner kit for each cylinder and one new head.  Truck ran great for four weeks.  Oil pump went out and had to have truck towed back to my house.  After a week of trouble-shooting I replaced the oil pump and after replacing the pump I drove the truck for about an hour and had it idling in the yard for about an hour.  When I walked around the right side of the motor where the turbo is I saw that oil was leaking out of it.  I then bought a brand new turbo and I still got the same result with oil leaking out of the turbo.  I pulled the exhaust manifold off and found that the exhaust port of #'s 3 and 4 pistons oily.  I removed the cylinder head and found diesel fuel sitting on top of the piston.  I then removed 3 and 4 injectors and replaced then with Cummings injectors..had heads vaccum checked but they were fine.  After reinstalling heads and injectors, adjust valves and injectors, cranked the truck up and got the same  results after having it run for about an hour.  White smoke out of exhaust with truck leaking an oily base substance through the turbo again.  It's either fuel or oil am not sure.  Cam shaft is ok...What is wrong with this select N14 Cummings?
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-----Question-----
Can you tell me what the problem is when you're getting fuel on top of pistons 3 and 4 under the same head.  The truck is not skippin; however, puffs of white smoke is coming out of the exhaust.  I took the exhaust manifold and only manifold 3 and 4 were wet.  I have a N14 Cummings engine.
-----Answer-----
A possible head cracked in intake port,a bad inj would just do one of the cyls and would probably missfire a few secs on start up.

Answer
The only way to find which it is is to get a 5 gal bucket of fuel & put dye in it then run it for a while.Remove the exhaust manifold & plug oil line to turbo.Make sure that BOTH return & suction are hooked up because Celect fuel pumps pump wide open all the time.