Luiz

Currently in my 69 GTO 400 4bl, I have a three port thermostatic/ported vacuum switch. One line goes to distributor vacuum advance, one to back of carb and the third goes to top front of carb.

I noticed another port on the side of my carb which goes nowhere. Pictures in the Restoration guide shows a line from here going to the vacuum switch.

Also the restoration guide shows what looks to be a five port switch. One line goes to the distributor vacuum retardation port which I do not have (because not CA requirements??).

So, am I suppose to have a five port switch? What do I do with the port that suppose to go to the distributor vacuum retardation port?

Thanks!

 

Old Indian

Luiz,
You're supposed to have a five-port thermo-vacuum switch. There is a rubber connector (old ones are a great source of vacuum leaks) that fits onto the TVS that reduces the five ports down to three vacuum lines. One line goes to manifold vacuum, one goes to ported vacuum and the third goes to the vacuum advance unit on the distributor. Ames Performance sells the five port TVS and a kit containing the 5 to 3 rubber adapter with the correct color coded hoses to the three vacuum ports.

Bill