276 stroker from 35 years of parts

[GB SISSON]

I now have all the valves installed and adjusted. Everything went well. After I cracked the lifter all the bolt squishing was lighter and at 40 in/lb they adjust firmly and none felt at all loose. I then installed that oil pump gear and am ready to install the crank. I have many questions about oil pans and bellhousings and starter plates. I have multiple cast and stamped BHs and 2 oil pans that look alike with the cleanouts. I also have the 4 bolt die cast seal holders at rear. I overhauled 2 8bas 20 some years ago, just replacing what came off, so there was no need for choosing of parts. I don't have a 'green bible' for the later engines so need help choosing what goes with what. Can I install the crank and then figure out the seals or do I need to set the rear one before the crank? Here's a few pics of what I have. My Best gasket 8ba set doesn't seem to include the rubber for the die cast rear seal holder. Any help appreciated. Thanks, GB