I have a 1964 Oliver 550 that I new needed some attention but once we got it apart the # 4 cylinder on the head evidently at some point ran a few steel marbles through it and gouged out the head and had evidently replaced the piston and jug but they had the piston in backwards as well. Needless to say I am looking for a rebuild-able head or a good one and any info would be helpful. I gave my mechanic Kents Gordons# and he was going to try with him but like I said I am open for suggestions. Also I am going to try to send a picture but I had to zip it for size and don't know if this will work but also any help in this area would be greatly appreciated. Thanks guy's