Don't think you need head studs. Stock head bolt is 1/2inch. I agree on the cometics though since you already have it apart. Are you running an LA or magnum block? I'm having a hard time finding a magnum M1 for my truck engine build, the duster already has one.
I'm running a magnum 5.9 with EQ heads. Glad you don't think head studs are necessary because ARP told me over the phone today that they don't make them for magnum heads.
This M1 was really hard to find. I ended up trading my air gap to a member on here for it.