Hey, Gerald:
Here's a pretty good history of the SBC from "Chevy Hi Perf."
Also:
If you really want to play with an older (80-85) non-perf oriented intake (SN 14057053), you can have mine, gratis. Lemme know if you really want it & I'll send it out ground & cheap, just happy to get it out of the basement. It needs to be cleaned out, was painted black (partially wire-brushed), needs to have the oil splash pan re-attached (not a big deal), but it is free to your door.
-Todd