Vulcan is a no-no on the AR side for receivers and from what I've heard, not so good for AKs either.
Had I not had such a problem with GT USA lying to me over and over again, I'd suggest one of their receivers with the UF holes already drilled for you. It might be an extra $40 or so.
I spent all afternoon drilling the rear trunnion and UF holes. I don't know how much money you make, but for me, it would have been cheaper to work OT at the office and then order the receiver with the holes pre-done. I don't make shit BTW.
Having the UF holes predrilled could help in aligning the trunnion and drilling those holes. I had to use a tiny bit to drill holes in or near the center of where I thought they should be. I then used a dremel and diamond bit to enlarge the holes and make them round. Good thing I did because I didn't line up the trunnion correctly to begin with!