David - I have been running the Atwood for over 20 years.
I use the Permatex Anaerobic Gasket maker, part number 51817 (available from Amazon).
It works with glow, gasoline and Diesel fuels.
As a matter of course, I replace the gaskets in ALL my engines with this product and NEVER had a leak.
Clean the surfaces well of all oil, assemble and you're good to go.
Bob Z.