Valve Cover Bolts/Studs

I have a 2000 and can't figure out what is supposed to be holding the valve cover on. Right now its leaking and I need to replace the gasket.

Currently it looks like the cover is held in place with a combination of regular bolts and/or studs with fasteners. Is it supposed to be a combination of both or completely studs/nuts or bolts? Or does it matter at all?

combination came factory. Some of the studs are meant to hold things like wire looms and coolant hose brackets. When I built my stroker I just put bolts in. 1/4 -20 iirc