Thanks Tim , my fear is once you change the fluid and you discover the gasket leaks it's too late . I do have a 1/2" thick finned alum. pan that I made so I can torque it down tighter than the stock pan . I guess I'll try using the same gasket again and see what happens.
I use the same gasket and have for several times. I have a new role of material (gasket) but each time I drain it the old one looks good. Good idea on the "O" ring and may just do that next time. Where do you get one that big and do you need to glue it together if you can't fine one that size?
If you go to an Industrial Supply place locally (or Internet) that supplies hydraulic parts for heavy machinery or farm machines, they will have or can get virtually any cross section diameter and overall diameter you can think of.
You can also go to a pool supply place and they have a large assortment of O-Rings for pool filters, chlorinators, etc.