That baby ought to have factory suggested settings for synergic pulsation @ your thickness.
Look to your owners Manual (pages 30 and 31)
http://millerwelds.com/om/o231242b_mil.pdfYou will probably not see any difference between 308 and 316 fillers as far as arc performance so you can start your trials with the settings for 308 if they don't have 316 in the pre-sets.
For fillets on 1/4 inch in the flat or horizontal fillet positon you could run anyplace between 250 and 500 inches per minute depending on what fitup and production factors you have.... The lower end of the spectrum will allow more "think time" for manual welders getting up to speed.
It should make beautiful welds........ If not let us know.