[RichardJ]

Whoever you get an engine from, you really want to be able to talk to the rebuilder in person.
On your remanufacturer.com page they mention 2-bolt and 3-bolt starter. You want the 2-bolt which means you can use the 2-bolt v8 style bolt UP starter and can still use the 3-bolt, that bolts BACK into the bellhousing.
They mention smog and AIR heads. You really don't want those, but if you do get them , you have to plug the holes.
The integrated exhaust manifold heads are 1979-85 heads and you REALLY DO NOT want those.
The heads will have spark plug holes, either for the older, larger gasketed spark plugs or the newer, smaller tapered spark plugs. The tapered seat plugs starting in '71 will possibly have hardened exhaust valve seats. That's around the time when the unleaded gas started.
I looked up some of those reman engine numbers you mentioned and found some engines pictured with fiber cam gears. Ask for the aluminum cam gear.