Monte Carlos are a popular swap for Gen III small blocks like the LS1 and LS6. They can make a ton of power and still be pretty smooth running. They are also 100 pound lighter than a SBC and are available with a decent 6 speed transmission. If you want to build more cubic inches, you can get an LS2 crate motor or start with one of the 6 liter motors from a Cadillac escalade. They are stroking these out past 427, in fact the new Corvette LS7 is based on the same engine.

Check out http://www.ls1tech.com

I am curious what road courses you plan to run this car on, and what class you hope to be competitive in.

Just some other options to consider.

Pat