I currently have a completely stock 305 small block in my 84 El Camino but I'm ready to make this thing a power house!

This will be my first real engine assembly besides basic fix-ups and service. Right now I'm taking a look at this motor here, but I'm willing to go bigger if possible.
ZZ502 Deluxe Motor 508HP 19331579 Chevy Performance Karl Chevrolet

I'm also looking at a 4L80E tranny.
http://www.jegs.com/i/Performance-Automatic/732/PAGM502HO-80/10002/-1

This is just research so I would appreciate any input you have regarding this setup or an alternative one.

Thanks!!