Which edelbrock heads do you have?
If you are looking for power up top, my guess is the cam or head selection. Your A/F ratio is pretty good for a NA car. Very constant. But my guess is the heads don't flow enough. The torque curve falls pretty fast after 4500 rpm's. If it was much flatter, you would see the 400 rwhp mark no doubt.
What octane gas are you running? Maybe running 91 will cure your pinging problems.
Scott