For checking out a used engine, I just read an article in Chevy Hi Performance Magazine. Still on the stands, it is a compilation of several good how to articles. Tells how to check to see if an engine should be good to drive or if it will need work. Sounds like a good buy for you.
For a carb, the Q-jet that's on there is tough to beat if it isn't worn out. Should be around 850 cfm. I have a 600 Holley on my 350, and it isn't enough. If you replace the carb, minimun for a 454 is 750 cfm. Definitely replace the intake, I switched to the Performer and raised my vacuum 2".
