What is the average temperature difference between the water in the block temperature and oil in the pan at operating temperature.

They tend to be pretty close(just normal block)

True.
Oil temp will rise pretty quickly with load, water won't unless the cooling system isn't big enough.

Not exactly a high performance machine lol, but my ‘16 Journey with a 3.6 will usually be within 10 degrees of each other. Coolant is usually 90C, oil 80-85C.

what is this "C" you speak of?

Normally C would be Celsius
EDIT
if you notice he is Canadian

With my Mega block drag car the water can be manipulated where ever you want its . Oil, that's a different story. Getting it above 150 F before a single run, good luck. Even a diaper hasn't increased it. Back to back runs at 80+ F ambient it might hit 180. This is with the temp sensor in the pan filled with 7 qts.
Doug

Oil is normally about 30F hotter in my half filled 440