[1LowToy]

The vacuum servo is for the exhaust heat riser. It blocks the exhaust from the exhaust manifold to make the hot exhaust pass through the intake to the other side when the engine is cold. This in turn warms up underneath the carburator to vaporize the gasses coming from the carburator.

For your full throttle press accellerator to the floor (engine off of course). Then check to see if carburator is actually opening the secondaries. The flaps on top of the carburator will not open but the ones below on the base plate should. It could be just a cable adjustment needed. I did find on mine that the transmission throttle pressure cable was set too tight. It went into passing gear real easy but it was also stopping the throttle cable from getting the carburator to open up the secondary flaps.

The vacuum line going to the back of the trans is likely to the vacuum modulator. This is for shift quality or in some cases is for the transmission kick down or passing gear.

Hope this helps