Alright,
I have the vacuum hooked up to the correct port on the carb. Now it will open in third gear when I go WOT, but shifting like a maniac in 1st and second it doesn't open? Any ideas?

-Joe

the hose goes to the intake manifold fitting behind the carb,not to anywhere on the carb

Is that an absolute? I have seen many set-ups running the vacuum hose to the vacuum port on the carb.

mine is hooked to the intake factory. Most carbs cant get enough vacuum

The "loss of vacuum" is what opens these things up. That is why they are open when the engine is turned off and shut when it is idling. When you go WOT, you lose vacuum, the flap opens. If it doesn't open in the lower gears, it is because the engine is not under enough of a load.

Joe,
Read this carefully.
Connect the vacuum hose for the vac pod to a MANIFOLD vacuum source, NOT to a ported vacuum on the carb!
Also, for the outer door to function as it was designed, you need the check valve installed somewhere in that vacuum hose between the engine and the vac pod. This check valve (It makes a difference which way it is installed) allows the outer door to open quickly under hard acceleration and close slowly when the manifold vacuum builds back. http://www.chevelles.com/forums/images/icons/icon7.gif

I do have the check valve. I guess I need ot tap the intake. Off to work I go.

If you have a vacuum source down low on the carb, below the throttle plates, that will provide manifold vacuum.

Mine is hooked to carb with no check valve,works great!
Gerry......

I found if you push an old main jet in the hose by the canister you can drill it for how you want the flapper to react.