I had this same alignment problem with my GMC 270, after I machined the 2 surfaces between the mating surfaces, when bolted together with the 2 bolts and 2 studs. I kept them together and installed the alignment rings into the intake and put the gaskets on and then was able to determine how thick a spacer I needed to make and put between the 2 manifolds. My spacer was 3/16 thick. This made the gaskets and ports align almost perfectly. Then left them bolted together and machined them that way. Or find different manifolds and start over. Either way its a pita.
Joe
