[19Fordy]

It has been my experience that on a 40 Ford if you are referring to the gasket that fits between the rear of the torque tube and the rear end housing you need to remove the torque tube and drive shaft if you don't want to cut the paper gasket. It's a lot of work.

I did forget to put one the clam shell gasket in place before sliding the drive shaft into the U-joint and transmission and DID cut the gasket to make it easier. I installed the cut at the top of the clamshell. Worked fine. No leaks. Use Permatex.

Personally, I would first try to install it by cutting the paper seal and installing it after removing the rear end bolts and unbolting the rear radius rods. I think that would allow the torque tube and drive shaft to slide forward and give enough space., HOWEVER, I AM NOT SURE ABOUT THIS. Others may know for sure. Make sure to use non-hardening Permatex and install the cut at the top of the housing. I made my own gasket .

DON'T CLEAN OUT THE REAR END THREADS WITH A TAP AND DO TRY TO INSTALL THE BOLTS IN THE SAME HOLES THEY CAME OUT OF. I NUMBERED THE BOLTS & THE HOLES BEFORE TAKING IT APART.