You could use a little steeper gear with your set up - maybe in the 3.55 range. Better seat-of-the pants feel ( typical with a smaller carb )doesn't always equate to better over-all performance. Ran a very similar engine set up to yours ( except 360 motor ) with a 3310 in a 4,000 plus pound automatic car and got it to run low 12.70's. Extending the squirter time ( longer duration ) helped for me. I also set the primary float level a little higher ( top of the sight glass ). Also went with a quick fuel secondary plate so I could change jetting easily. Can't remember for sure, but I don't think I deviated much from the stock jetting - maybe 2 sizes richer on both sides. Are you still using the stock sec vacuum spring? I think it is plain steel in color. I believe the stock PV was a 6.5 on that carb. Stick with it if you are idling at 9" - seems a little low? Don't know how fast your advance curve is, but you could try slowing it down a bit and see if that helps.