Did your stock pan have a baffle? A windage tray will do nothing for controlling the oil in the sump under hard acceleration. If you didn't it's not surprising the engine starved for oil as I'm sure you are pushing some serious HP with a 7000 RPM redline. With your new deep oil pan it shouldn't be much of an issue though, they are designed to help keep oil in the sump at all times.
You could always pry the 'window' flaps open on the tray a little more for added drainback, the passages are a little small OOTB.