Ok guys, back on topic
Got the engine plate thing (between block and tranny, flexplate and TH400 spacer sleeve installed (had to grind the leading edge of it down to get it started in, I was sure I was going to break the damn thing).
Cleaned up the exhaust manifold flanges and then found out that the heads on the old engine had all 3/8" bolt holes for the manifold bolts and the new engine is 3/8 for the center outlets and 5/16 for the outer outlets. Google search found that the 304 heads had all 3/8" and the 360 heads had the smaller outer holes. Didn't have the right length 5/16" bolts, so going to get them today (from what I've seen searching around, the special gun-drilled bolts were not needed once you use anti-seize, easy enough to put a wrench on them to check that they're tight every so often.
Cleaned up my Mean Green starter to have it ready to install.
Getting there, slowly. Had to fight the urge to stay inside and warm vs. getting at it last night. Just above freezing in the garage, it was around 10° outside last night.