1972 Chevelle SBC combo

Thank you everyone for all of the comments. I wouldn't consider myself a "newbie" per say as I started following class racing more than 30 years ago as a teenager. I attended several Divisional and National events per year with a Division 3 champ in the late 80s/early 90s all the way from Florida to Canada. About 15 years ago I had a '95 Impala SS that I ran in Pure Stock while living in NC. I have never owned a Chevelle and thought with a gear and converter change I might be able to put an engine together to run the index and have fun but didn't know which combination would be best. I also didn't realize that competitive long blocks cost the numbers you guys are mentioning. My wife and I are both high school math teachers and with a daughter in college that's out of the question now. However, it's not unreasonable for us to start gathering the correct casting heads, intake and carburetor as I run upon them.