I may br crazy, but WHY WOULD YOU WANT MORE FLUID CAPACITY? I can see the benefits of more capacity in something like a differential or manual trans, but in an auto trans??
The diffs and mannys have NO COOLING MEANS with respect to fluid being pumped out to a cooling device.
An auto trans has a cooling means-- it pumps the fluid to the radiator and/or aux transmission cooler.
IMO, extra auto trans capacity is a waste of money (more expensive fluid changes) and ground clearance.
If you want your trans to run cooler, add an aux cooler.
If you want the fluid to last longer, add a separate filtration setup.
Additional transmission capacity is the wrong way to try and accomplish some things that are better achieved by different means.
It's odd to me that sump-type systems are made larger and larger as the "performance" application becomes more severe. Yet, as you reach the highest levels of performance, they do away with the sump all together and go to a "dry sump" system... What's wrong with this picture????
The ultimate setup imo would be a dry sump auto trans setup, complete with scavenge pump, cooler, filter, etc.
jlh