About that ebay offer for a b20 rebuild for $600 shipped, which lists the following included:

"New Pistons
New Rings
New Timing Components
New Freeze Plugs
New Installer Gasket Set
New Main Bearings
New Rod Bearings
New Cam Bearings
New or Reground Cam Shaft
New Push Rods
New Oil Pump
Re-machined Block, Crank Shaft, Connecting Rods and Cylinder Heads"
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33615&item=2474903105

I need to itemize further, or just pays my money and takes my chances

Oil pump reinforcement ring.
New lifters.
3 angle valve job
New valve seals.
(New valves, springs, keepers, guides, knurling?)
Hardened seats installed. (I have a 73 and a 74, so hardened seats are already in, I think. I will choose one engine to do, probably the 74 since it's out.)
K-Cam ('74) or D-Cam ('73)
crank/rod/piston balancing.

Anything else?

I think I'd be happy with original felt front and rear seals, unless someone says different definitely.

My next step is to pull the 74 head and pan off and peek the cylinders, gauge the journals, eyeball the valve seats, measure the lift, and decide if rings, bearings, cam, what all is necessary.