Edelbrock models 1405 versus 1406 carburetors

Bone stock 383 2bbl except Mopar M1 dual plane alu intake, 1405/1406 carb, HP exhaust manifold, 2 1/2 dual exhaust and blocked heatriser.
1468 accelerator pump, inner hole and 43 nozzle.
Ignition initial 10* and total 35*, ported vacum.

Now I've tried everything in this tread except "drilled another transfer nozzle closer to the early feed tubes" and stil got wot bog when flooring.
I've tried both an 1405 and 1406, same wot bog...
My O2 sensor lean out when flooring from cruise but if I'm a little gentler on the pedal I've got a little rich AFR around 12-13 at power and around 11-12 at wot so jetting should not be the problem.
I've tried add some weight to the air valve to make it open later (from 122g to 130g), no change.
I begin to suspect the blocked heatriser as when I do all my test it's around 50 degrees here.
I really appreciates if someone have any idea except "buy an Holly" or "600cfm is to small for an 383"
I'm running out of ideas...