Vacuum advance and ported vaccum switch

[carmangary]

I spent a few days figuring out where all of my vacuum lines go and after all of that I found out that my "Distributor Thermal Vacuum Switch (DTVS)" is bad. And, it appears that it is no longer available (for '79 4.3L Cutlass). The thing either switches between "checked" manifold vacuum < 66F and unchecked manifold vacuum at > 66F. By checked, I mean that it has a built in check valve which will make it have the highest manifold vacuum until the oil temp is >66F.

66F is a pretty low and I live in NC so I am thinking of just bypassing the thing altogether so that it I always get from normal manifold vacuum. Unfortunately, the switch failed in the "checked" position.

I found one at a junk yard but can you believe that it is bad, too? Ugh.

Have any of you run into this? If so, what did you do?

 

[Bonnewagon]

Rockauto lists it.

 

[carmangary]

They list one but it isn't right. It's supposed to have 3 ports but the one they have has only 2. Maybe there was a tech service bulletin that changed the way the emissions stuff was connected later in life of the cars. But, I haven't found any info that support that idea.

 

[Bonnewagon]

I've run into that with Rockauto. Then when you tell them it's not the right one, they say that's what the supplier specified, so they did nothing wrong, and you must pay shipping to return it.