The Kings rod bearings that came with my Scat kit didn't clear the rod journal radii. I order a set of Clevites, which fit perfect. However, my 1st set of Clevite mains were so loose, they would barely stay in the block - I sent them back to Summit & got a replacement set that fit correctly. I've wondered about the folks that just assume all this stuff is going to work as-is & screw it all together without checking. Maybe that was your "guru".
My cylinders are round, straight, & consistent within my bore gauge's ability to measure, so I think I'm Ok there. Always on the lookout for the next thing to bite me in the butt, though.