New Guy, 1965 Merc 350/35hp

[DerekM]

Hi all, new to the whole boat thing, so I sure could use some help. I have a 1965 Mercury 350/35hp motor, great little motor with plenty of power. the only problem I am having right now, is gear oil is coming out where the prop is. When I filled it up with oil, water came out first, and then the oil. Can anyone tell me what seals/O-rings need to be replaced? and possibly a part number and place to find such items? and would I need any special tools? I have a good mechanical ability, and should not have any problems if no special tools are required. Thanks