Carb issue ?

[Nobbynumbnuts]

On heavy braking from speed , the engine wants to stall. I get round this buy blipping the throttle, which is now getting to be a tad tiresome.
Tickover isn't set too low in my opinion.
I assume it's carb related. Any ideas ?
Ta.

[dicky]

Check for anywhere that air can enter after the butterfly.
The rubber boots between the carbs and the inlet stub are old enough to perish and crack.
The plastic Air-Cut valve covers crack, mostly the RHS one as it can get some sun.
Vacuum tubes to the fuel pump and tap.