I will check that out today. Based upon head casting number, this was either made for and/or installed in a Massey Harris combine. As per the attached table, no "10039" head casting number is shown. Also have no idea what the "F" in the engine serial number indicates--can't seem to find a specific reference anywhere. Maybe "F" is for "Farm"? Still trying to view block casting numbers, but can't do so without tearing off accessories. Ordering a manual on Chrysler industrial engines as there's not much posted in the open regarding them. One thing unique to me is what appears to be some sort of oil passage bypass located between the dipstick housing and rear of starter--I reposted picture below again. Have seen a picture of a conventional spin-on oil filter mounted there upside down--looking for the picture again. In any circumstance the versions of engine blocks with and without this "thing" are many. I continue to scrutinize engine pictures for clues. I appreciate all the thoughts and opinions--please post if you have more! Thanks again to all!