Hi guys
I have a 77, 2ltr, it originally had an air injection pump, but I have removed the pump and all the plumbing, and am now running a single carb with the original vac dizzy with the two vacum ports, there is only one vacum take off on the manifold, witch I have used to connect to the dizzy.
What should I do with the other dizzy port, plug it or just leave it open?
thanks Rob

The vacuum advance connection to your distributor must come from a port just above the throttle plate. It goes to the connector on the domed side on the vacuum can. the other connector on the flat side should be left open.
If your carby does not have this port then do not use a connection on the manifold. It will give vac advance at idle rather than partial thtrottle which is where you need it.
Jeff

Thanks Jeffh
I just dont like things being left open, but if thats the way it should be then I will leave it be!
Rob....

Think of the second connector on the flat side as being a vent.
But do make sure the connector on the dome side is connected to ported vacuum not manifold vacuum and is timed as for a single vacuum distributor 7.5 deg BTDC
Jeff

Isn't the retard side meant to be feed from the head side of the butterfly? If so it wouldn't be too hard to fab something up like a hosetail tapped into the manifold. Also I recently read Shad Laws (A knowledgeable guy IMHO, just look at those Nickies) Ignition Timing 101-103 series and he stated that unlike EGR valves, dashpots etc., the retard was one anti pollution device he left connected as it didn't adversely affect performance or economy.