Hot Rods Replacing a 700R4 Speedo driven gear

I've verified that the driven speedo gear in my 700R4 is broken. It looks like it should only take a couple of minutes to replace. When I remove the housing for the driven gear (just that housing, not the tranny driveshaft) should I expect a lot of transmission fluid to drain out? If so, can I reduce this by putting the rear wheels up on a ramp?

 

Raising the rear of the car will help...I prefer jack stands to a ramp, though.

I hope you got the right gear.

 

I think I drove the left side wheels up on 2 x 6 boards. Not too much mess.

Phil