Mounting exhaust manifold to Aerovee with exhaust flange gaskets. Drilled flange keyholes to round the straight selction of 'keyhole' to provide thread clearance for square bolt alignment. Much pulling and pushing of exhaust tubes to align and install bolts. Technique for final flange (#1 cylinder in this case) was to pull flange into position with opposite flange bolt in place. Pull the exhasut pipe while tightening opposite flangebolt. Last flane bolt could then be aligned and tightened. Flange bolt bottomed before bolt head engaged flange facing on cylinder #1. Used washer for thread take up. May try running a tap into the hole.
