If you want big screaming power here ya go:
A. Use a Holley 750 DP
B. Use an Edelbrock Super Victor Vortec Single plane intake and have it port matched to the Vortec heads you have.
C. Choose a cam lobe from this link and go from there. http://www.carcraft.com/techarticles/116_0311_cheap/
Scroll down and click on the small yellow chart above the Royal Purple oil quarts. Those are some mean cam specs that you would want probably. You can go with larger lift cams if you read D and follow suit.
D. Are you willing to spend money to take that engine apart and modify the heads? It's worth power.
You could machine the valveguides down to accept MORE than .485 lift which is the maximum you can run with stock Vortec heads. Also since you'll be choosing a killer camshaft, bigger stiffer springs would be a wise choice. A performance oriented valvejob would be worthwhile also along with pocket porting and smoothing of the runners, maybe even combustion chamber polishing. If that's something you want to do, you can then just get a bigger cam to start with instead of a small .485" lift cam. Aftermarket Roller rocker arms would also enhance high rpm operation while adding power.
This is what the "Cheap Street" racers are doing and ya know...with a 175 shot they are running high 9's and probably making 600+hp...Goodluck!