On further consideration, the Vortec heads have higher static compression than stock heads and can take a little more duration without bottom-end torque going in the toilet. So use the longer-duration 12-238-2 Comp cam rather than the 12-235-2. If you were sticking with 76cc chambers, then the 12-235-2 would be the better choice.
You might also look at the Dart 127322 heads. 8-1/2% bigger intake and 13-1/2% bigger exhaust valves than Vortec heads, which makes a huge difference. In that setup, with the 12-238-2 cam, you'll get 360 hp at 5000, 425 lbft at 2500, and it'll wind to 6000 rpm.