[xlr8or]

I have the same carb on my truck and had the same problem.
I moved to the 7" spring, (heavier spring means more vacuum required to stay in cruise mode so the idle to WOT is quicker to power mode), went to the innermost hole on the pump, and richer power mode on metering rod and that cleared up most of it. It seemed to improve a little be retarding the timing a couple of degrees as well. I now run at an initial timing of 10 degrees BTDC and max out at 34 degress BTDC at 2400 RPM.
Now it only chokes if it sits idling for a while just prior to jumping on it.

Sorry Mr. Fixit I'd rather give up a few horsepower on the top end and not have to replace power valves every 6 months.