Gary,
although the factory didn't use one,some people like to add them to rear sterling 10.25 diff's too (i don't)
can you use a gasket on the oil pan if you wanted?
HammerDown,
why do you suggest ultra grey vs ultra black?
http://www.permatex.com/products-2/...torque-rtv-silicone-gasket-maker-82194-detail
http://www.permatex.com/products-2/...l-resistance-rtv-silicone-gasket-maker-detail
Don't use a gasket it will leak... I know.