When reattaching the intake manifold, I noticed that the tops didn't quite match up perfectly with the cylinder heads. I suspect that the manifold got twisted slightly when welding the attachment brackets near the bottom. I tried reheating the manifold and bending it back, but it wouldn't budge. I decided to make the manifold "adjustable" so that it would fit better. I cut the manifold right at the weld in the middle of each of the down-tubes, and connected them back up again with the same fuel filler hose that attaches it to the cylinder heads.
Total Time: 4.0 hrs.