Honestly since your almost over the threshold @ 3000rpm the 3.5 valve should be fine, but ultimatley you'll have to experiment to see exactly what the car wants so dont be afraid to make minute changes from weekend to weekend and see what works best for your particular set-up.
Note: I had a similar set up like yours on a 350 smallblock race only motor, Holley 750 dp with a proform center section, but I went with no power valves and had the carb jetted 82 square, worked really well for me.
Goodluck, Charles