If the oil pump turns out to be contributing to your leak don't despair. Mine was dropping oil like the Exxon Valdez, when I pulled it off the o-rings were uber flat. I had bought an o-ring kit at Harbor Freight for like $10 a while ago and it finally came in handy, all the needed oring sizes were in there. Clean it up, put in new orings, a little gasket sealant because I really didn't want to ever have to take the dumb thing off again, some hex bolts because phillips are hard to torque properly (one note on the hex heads, the lower left bolt is a bit close to the pump body so it's not easy to put on with a socket, in retrospect I think I should have went with the allen head bolts) and the oil leak is gone. I've only been able to idle her so far, but I've revved her as far as 6k rpms (spike, I'm not holding it there without a load, just gives me the creeps) and no leaks so hopefully all is well.
Brandon