Oil pump gasket?

Had my oil pan off today and decided to pull my Melling HP72 pump (340) so I could grind a sharp corner off the casting. It actually hit my Milodon pan and dented it, anyway it had no gasket. I didnt use one when I assembled it, but after holding a straight edge against the mounting flange it was not perfect. There was a .010 to .015 gap in the center. I've never checked it before so make a gasket, use PermaSeal, RTV or just do nothing. Worried it might be sucking air. Haven't checked the main cap yet.