I wouldn't use a deep tranny pan that doesn't have internal baffles in it to control the oil. The tranny has windage losses just like an engine. Not the hot setup to have a gallon of fluid slinging around on the internals when you launch and all the fluid rushes to to the rear of the pan and climbs up into the case. Yet another parasitic loss to slow you down. A good large cooler is a better way to control temps
and add oil capacity at the same time. Also a filter extension that isn't sealed right will burn up your tranny in record time if it sucks air.