Edelbrock models 1405 versus 1406 carburetors

As you can read I've tried both 1405 and 1406 and I get the same bog at wot no matter how I've jet/rod it to an acceptable AFR and I've tried every spring and ended up with the stiffest silver spring (8hg/in).
I get real good AFR in every situation except when I hit the pedal to the floor, then I get a lean out for a second that even stall the engine in some cases.
You can forget about the shaded area in the chart, every engine is unique and needs to be tuned to all the circumstances like deleted EGR, intake manifold, exhaust manifold etc.

I've now added more weight to the air valve counter weights, I'll get back with the result when I've tested...

I really appreciates if someone have any more idea...