Reply to "Engine just dies...."

If the Carb is the only thing you changed and the symptoms are only apparent on braking then it sounds to me like fuel slosh out of the bowls and into the vent tubes causing the engine to go rich and stumble.

This is often reported as more of a problem on Pantera's with the mid engine design and under braking as fuel from the secondaries sloshes up the vent tubes and floods the engine. You can set the secondaries float just on the low side to help and/or you can get extension tubes that extend the vent tube to help prevent fuel sloshing.

You say your car is running on the rich side anyway, which may be adding to the problem. Did the carb coming appropriately jetted for your engine/conditions?

On the classic Holley carburetor, the accepted method for setting the float level is to run the engine until everything is warm, and with the engine at idle, unscrew the plugs in the sight windows for the float bowls. Raise the float just until fuel begins to escape from the window, then lower the float back down a bit and lock everything in place. So you really shouldn't see any fuel in the sight glass if properly adjusted.

Good luck,
Julian