Replacing 727 Low/Reverse Band Pin O-Ring in Car

Hey guys,

Have a 727 with a leaky low/reverse band pin o-ring and have some questions on replacing it in car.

I think I have the process understood from searching the site (Remove trans mount/tailshaft. remove pan, remove valve body, loosen low/reverse band, and push pin out far enough to replace o-ring).

My question is more on how are you supporting the transmission during all of this?

I'd normally put a piece of wood & jack under the transmission pan to remove the tail shaft, but what about when removing the valve body? If I remove the tail shaft first, it wouldn't be be supported by the mount any longer.

Am I missing something or is it OK to have the transmission unsupported for a short time?

Will be doing this in my garage with the car on 4 jack stands.