I think the oil comes out of the exchanger 10F lower than the Jacket water, and runs in the engine about 10F lower than that due to heat radiating from the large engine block. That's a general guess, I don't have any instrumentation on the engine, nor alot of run time. I have powered the house on it a few times, but it is a standby generator, and we haven't had a power failure since I got it set up.
Scott E
PS
Darren; I messaged you about your ford truck off the list...I'm thinking about getting one (6.9L F-250) what do you think of yours? Anyone else got a comment?