I did check for valve spring bind. And there was none. Except... there was bind.

Turns out that my machinist friend and myself both failed to notice the damper springs had to be removed. The L31 valve guide is machined so it closely fits the ID of the stock springs in order to damp oscillations. Well, the ID of these springs matched the stock L31 parts and the OD of the damper was the same as the OD of the guide. Can't put two pieces of matter in the same space at the same time. But because it was inside the primary spring I never noticed it when I was checking the primary coils for contact on the vehicle. It was very good to find this, although it would have been much better to find it before I did damage. So I'm out the cost of a set of GM performance head gaskets (about $36) and a ton of time. Engine starts and runs.

Right now I'm sitting and waiting for silicone to cure at the timing cover. The adapter I built to run the Vortec plastic cover spaced the cover forward about 1/16 inch roughly. This put a little extra pressure on the lower portion where the pan gasket sits. All the parts sealed tightly. But as the engine warmed up the cheap plastic cover decided to change shape slightly and conform to the pan which left a small gap at the pan/block/cover intersection. No problem. We've got some really good sealer here so I filled 'er up. In a few minutes I'll fire it back up, do a crank relearn, check the distributor / cam sensor position, and I'm outta here.