The guy who did mine had me mount them both up to the block and tighten them up then pull them back off as one unit. I didn't question him as I figured anyone who once ran 30,000 rebuilds a year through his shop knew wtf he was talking about. (He had one of six shops on the west coast that ran numbers like that but its now just him and his son... I guess times have changed ) If the alignment rings are a a factor then take them in with the manifold and have them dressed up as well.
