[Rx:GTO daily]

I've looked thru all old posts on this, my issue seems a little different. In the last 2 weeks, occasionally on morning starting, carb floods and spews gas onto manifold. This occurs after depressing throttle fully to set choke and engine starts quickly, then bogs, blows black smoke. Often, a few quick stabs at throttle will clear this up and engine settles in at fast iddle till warm. Sometimes/not always takes a larger than normal tap on throttle to kick choke off. Car then runs very well. Today, same thing. Just got gas and added carb cleaner to tank. Was out having "normal fun" and after leaving a light at WOT then slowing for traffic, it was obvious it was flooding again. Pulled over/car died/took off RamAir pan/wiped up fuel/started car and all was fine. Tried same thing at a few minutes later with same results. Seems as long as I stay out of the secondaries there is no problem, even did prolonged highway run. Runs and idles perfectly.
Specifics of car:
70 RAIII 400, TH400, stock RAIII carb (rebuilt 5 years ago), mechanical Carter fuel pump and in line filter after pump (none in carb)... pump and filter installed about 3000 miles ago. Never any issues till now. Car is driven every day weather permits... never sits for prolonged periods. All linkages look fine/unbent/not binding on anything. I have not needed to do any kind of work under hood, other than polish the valve covers in a long time, so it's not like anything has changed or been hit/bumped, etc.
My first thoughts were stuck float or garbage on needle seat, until this occured after driving at WOT. Could still be, just seemed odd.
Thanks in advance! I appreciate any ideas before I tear carb down or send it out for work.