Well the leak appeared to be very slight, so I decided to go ahead and run the car yesterday at my local track during open practice.
Holy crap, this car is fun to drive. Having spent the last two months trying to get a setup that works for my two whee drive car, the way this 4 wheeler hooked up with out hardly changing anything was impressive. The car cleared our triple jump with no issue, and did pretty well in the sweepers. I loved having so much on throttle steering.
We had a light crowd for our Friday night club race yesterday, So the race director let me run the car in 4 wheel sportsman (I was one of three in the class). I didn't do so bad, and finished second, but I was a lap back.
So this week I will replace the diff seals, and hopefully have another fun time with car next Friday.