I don't have any way to check for specific hardness. I didn't notice any kind of washer when I removed the drum originally, so perhaps the original is a hardened drum. It's now just sitting in a box of spare parts if anyone has a specific need for it.

Thank you very much for looking that information up.

The trans is in the final stages of being built. The forward and reverse drum have been assembled, and fall within spec. The pump will be getting cleaned and checked tomorrow.

Should I air check the servos before I install the valve body?

Also, are there any pitfalls to avoid when installing the VB or inserting the parking pawl down into the overdrive section?