"Milky grayish oil"- - - - -definitely not a good sign. I'd suggest draining as much oil as possible, drain all the coolant to prevent further contamination, and refill the crankcase with 4 quarts of inexpensive oil and a gallon of Diesel fuel. Run the engine for a minute or less, 3 or 4 times, to flush as much contaminated oil as possible out of the rods, main bearings, valve train, etc. Don't let it get too hot.
Then pull the cylinder head and look for a damaged gasket or other evidence of incorrect assembly. It might also be a good idea to get the head pressure tested by a machine shop to look for cracks, if nothing obvious is found wrong with the head gasket. Good luck!
Jerry
