John  I don't know if my lasted  message got threw.I have the B.F.AVERY book in it it list Hercules IXA 3" X4" 113ci for the engine in the general and the IXK 3 1/4" X4" 123ci or the 3 1/4" X 4" 133ci for the avery model A.I am not in a hurry to get the general restored. I have an avery A that is  a part that I going to try to finish first but would like to find the right engine for the general if I could.This book also list 5FA38 for the year 1940 I take it that is a start number so if I am figuring this right my tractor would be avery late 1939.If know any sites I might be able check to locate the right engine I would appreciated.
        THANK YOU Steve