Steve,
If it was stumbling while in the corner, it is not likely to be fuel pickup as there would not be enough time for the air to make its way into the carb bowl.
Raising the float seemed to partially correct it so it is likely fuel sloshing away from the pickup in the float bowl, or the carb is a side float model.
There are aftermarket bowls designed to help slosh:
http://www.braswell.com/html/severe_bowls.html
If it is a side mount float carb you could switch to a center mounted float carb which fares better under lateral gS.
Hope this helps,
Jim