since its your 1st year and you are gonna be realistic and just get valuable seat time ...i would seriously think about the base line GM crate engine for $1500.00..with their cam its rated 260hp and 350ft lbs of TQ at 3500 rpm...you could always put another cam shaft to find a little more Bottom end...work the bowls on the heads,angle mill them for a little more Compression, little intake work...and you could have a decent NEW engine for under $2500. by the time you add your carb, intake,HEI dist...you may end up with an engine making 400ft lbs of Tq...
By the time you go trying to Piece an engine together you gonna have more then $2500 in it anyway..don't believe me...go try it
thats the route i would consider if it were me anyhow..
http://www.jegs.com/p/GM-Performance...52506/10002/-1