If you should replace the pump chamber gaskets you very well may have lots of trouble installing the pump.
Some of the aftermarket chamber gaskets are thinner than the the original Ford gaskets. There is a boss at the back of the transmission that is there to align the pump when it is installed and it is a very close tolerance fit. If the gaskets are too thin it could make it impossible to install the pump. I have heard of the tabs at the front of the pump chambers being ground down some to allow installation.
Best not to remove the pump chambers if at all possible. About the only service you could do on the valves are to see if any of the springs are broken.
"If it ain't broke, don't fix it!"