your not gonna achive it with stock heads or pistions and the cam won't help much because you have to have the engine built to the cam basicly, you could get away with only a mild cam assuming you have 8.5:1 comp, with leaving the engine stock, the only way to make power is to use forced induction or N20. get your compression to 9.5:1 by getting a set of good flowing 64cc heads with 160/202 valves ( you probably have 76cc ), then get a mild cam that will run from 2k but nothing too wild, you could run a slightly hotter cam but run rhoads lifters ( milds out a cam at low rpm ), a set of long tube headders with 1/5/8" primaries, a holley 650 carb on a good dual plane intake. I just ran those numbers through Dyno 2000 ( dyno program ) on a stock bore 350 with a light cam and 9.5:1 compression and it reached 300 HP at 5k, and there was 2.0 timing advance figured in. as you can see it is going to take more than bolt ons to make 350 hp