Answer to "Old Style Water pump Series 60 Detroit"don't worry about the newer water pump. Your thermostats will maintain the 190 temps. The newer water pumps are higher outputs for egr engines, and they will just be fine on the older engines.
Answer to "Why my Davco Fuel Pro is draining below collar and doesn't fill?"http://www.davco.com/diagnostics.html here is the Davco website help page
Answer to "Oil sample showing coolant in oil"before you condem the head gasket, you could have a plugged weep hole on the water/pump. Also the air/compressor, is water cooled and you might get oil in the water there. I recommend pulling the oil pan and put pressure in the coolant system.