Don't go over 208 intake duration at 50 lift, the VooDoo "00" cam referenced above is the biggest cam you could use in that combo and still get decent mileage and lower end power. Keep in mind that the stock 318 cam intake duration at 50 lift is something like 178 degrees. The abovementioned cam is 30 degrees bigger at 50 lift. The Edelbrock Performer is something like 204 at 50, the Comp high energy 252 is something like 205. I'd also look at the Comp XE 250. Check out the dyno charts compared to the next two sizes of the Comp. Admittedly they are in a chevy engine but the XE250 makes a pretty strong statement.

R.