Looking to buy my first Duramax! Buy or walk away?

Went a looked at a 2004 chevy Kodiak 4500. Has 143xxx miles on it. New injectors 1200 miles ago. Checked engine oil level and it was about 2 quarts over full. Started engine and noticed engine oil pressure was high. Oil pressure guage read roughly 67 psi. Air temp was about 80 degrees when starting engine. Is this common or is there a issue?

Cold oil 67 psi is normal, once hot it drops quickly. Oil smell of fuel? LLY isn't known for putting fuel in the oil but if an injector was hung bad enough it could have washed a cylinder wall down. Possible coolant, LLY is known for having crappy head gaskets. Upper Radiator hose rock hard after the engine has completely cool?

The oil did not have a diesel smell. I did not check the radiator hoses after running. Coolant level was correct which could have been fixed before I showed up to look at it.

Take the oil dip stick out and put a drop of oil onto a white paper towel or napkin. If there is fuel in the oil it will wick out farther than the oil and look like a halo. If the injectors are not visible from the outside it is an LB7 engine and the furl return lines could be leaking under the valve cover.