Hello out there. I'm new to this discussion board and just bought my son a 1941 John Deere Model H. I want to drain, flush, and refill all the fluids. I was wondering whether or not synthetic oils and lubricants can be used? I know they have a tendency to find fissures and or other small imperfections in gaskets as opposed to conventional lubricants. Anyone with any experiences, whether good or bad please help me out. Thanks in advance.