Strange engine code

[JSabah]

I’ve just picked up 3 Power Wagons and in trying to figure out exactly what I have I found that one on the engines has a code that starts with an N306. I can’t seem to find anything like it on line in the engine decoders or lists. The whole engine number is N3066900AL (the last 0 may actually be a C). Anybody know what that engine may be from and if it is a 218 or a 230?  Thank you 

[Dozerman51]

It’s CAL not OAL. The 230 in my WC-12 had a serial number of DR0014232CAL. The original T-211 motor was replaced with this one in 1957. They had written the replacement date and year on the cab door opening in grease pencil. Don’t ask me it stayed there from 1957 until I purchased the truck in 1987.  It did say “New” motor, not “Rebuilt” motor. I have heard these were factory built replacement motors and the Serial number pad was left blank. This was done so the DMV in that particular State could stamp a serial number on it which was used as the VIN number. Perhaps it’s true or maybe not.  It could also be a rebuilt motor that had the original serial number ground down and a new one stamped in when it was installed in the truck.