85 300D: Shut off valve replacement, two gaskets or one?

[rbc]

I tacked this question onto my original post, but the subject line was misleading and out of date so I am posting as individual post (hoping this is ok with forum rules).

Replacing shut off valve in ca-model 85 300D and found that valve coming off engine only has one gasket seated between ip housing and so valve. Most descriptions of replacement, including dieselgiant, cite a metal ring and TWO gaskets.

Am I ok to just use one new gasket pressed between ip housing and new valve?