Having installed two of the adaptor plate setups, I would suggest that you use #2 Permatex as opposed to RVT. Likewise on the thermostat housing. While RVT is a good product in certain applications, it is most effective if applied, snugged, allowed to set up and then torqued down. You can torque the #2 and you'll be good to go.
I have the instruction sheets for the adaptor plate installation in my Webshots album. Click on "full size" so you can read the print. Hope this helps.
Dave
