Weird Oil Leak

[ModelAMadMan]

I searched the forums and couldn't find anything that directly relates to my problem. I had my engine rebuilt not too long ago and I have had a pretty good oil leak. I contacted the rebuilder about it and he kept on coming up with lame excuses and it's gotten to the point where I don't want him touching my car anymore.

Here's the problem. The oil leaks out of the hole where the cotter pin is with a thin steady stream. It will not leak just idling, it will start to leak after driving it around a few minutes. I took the fill cap off and drove it around and it stopped leaking after driving it around but now only if it's on flat ground. When I pull up into my driveway on a small incline, the steady stream starts up again.

I have a little bit of mechanical knowledge on the Model A but not much. So hopefully this is an easy fix or someone would be kind enough to explain the steps how to fix it. Could it be as easy as having too much oil in it??