Well, got some follow-up news, but unfortunately not good news.
My buddy got new bearings rolled in the Tunnel Port, so I rolled down this morning to go help on the dyno.
First lick out of the gate was 610 hp @ 6500. We didn't know much about the combination since someone just brought the engine to my buddy's shop to dyno, so we started out conservatively at 38° timing. It showed on the plug that it wanted a little more, so we gave it 41 (from my experience, the TP engines like 40-42°). It dropped 10 hp and then when we put the timing back to where it was, it lost 10 more. That's usually a tell-tale sign of bearing issues, so we shut it down before it did something bad. Cut the filter open and there was copper all in it, so that's that.