Al, i had a 300 shot with stock motor and fuel delivery. Thats about as far as you want to take it without better fuel management system and fuel pump.
My buddy got better HP and TQ increase with 200 shot, because he had a cam and ported heads. I would do both in your case, since it looks that your are about to get serious with spraying...
Abandon your stock exhaust, GEN 1 breaths much better with a set of Belangers and 3" system. (and you'll loose an easy 50lbs...)
Be sure you have replaced the original head gaskets, they will blow quite soon...
If you want even distribution, why not go this route?
Let us know how the spraying progresses....