Not sure what this is. Got at an auction, it was mounted to a homemade tractor frame - I guess it was not uncommon to do in the 1930's. here is info that I have from the engine: It has a FERRO stamped on the engine left and also B107. The engine is shown in the picture and you can read a stamping on the block - 346709. It has a serial number 3037750 that is to the left of the magneto. It has a Bosch Du4 magneto Mod. 4 with the serial number 2171295. Any idea's? Had and uncle that thought it was chevrolet. Someone else thought it was ford, but when I looked online, the head (removed and not in picture) looked different. Hopefully the picture makes the trip - first post to this group.