Update :

I checked a few things last night,
#1. Fuel pump pushrod looks brand new
#2: verified no obstructions in the fuel filter
#3: baselined the carb back to 78's all around ,per factory

Fired it up this morning, did as Fast68 instructed, revved up to 3,800 then pushed past, it climbed about 5,200 then I let off. It felt good.
Took it for a romp,.. pulls clean to about 5k in second then manually shifted to third.. not a hiccup. I'm not sure if re baselining the carb helped, or if I was just being hyper critical (paranoid) on the first few test drives after the new head install, but it seems to be running just how it should, just with some more "umph"..

Thanks to all for your input and suggestions, I appreciate it. So, next step will be some track time to quantify my improvements, hopefully move forward past my previous 12.55 best et.