Classic/Antique Car Repair: thermal vacuum switch replacement, 67 impala ss, heater control valve

Question
I have a '67 Impala SS with 327ci/275hp.  The thermal vacuum switch that is
in-line with one of the heater hoses that goes into the fire-wall and also has 2
vacuum lines attached recently broke apart due to rust.  This component has
never been replaced in the 40 years that we've had the car.  When I checked on
the internet and called several shops, they say that there is no manufactured
direct replacement for this part.

1. is it OK to bypass this part and if so, what are the implications?

2. if I need to replace this, how do I go about cross-checking what make/model
part will work since there's not one specific to my car?  Or should I just keep
looking until I find an old original in the junk yard that may be just as rusty
as mine?

Thanks for the help.
---Dwayne"

Answer
You can bypass this device, but you will want to install some way to turn off the heat for summer and turn it back on for winter use.  You can buy a manual heater control valve from NAPA, and just manually turn it off and on as needed, or you can peruse their "buyer's guide" for heater controls and find one that is close enough to use on your car.  This is not rocket science - all the control is, is a vacuum operated valve that controls the flow rate of hot water through your heater core.  The vacuum is variable, in response to your setting of the heater controls and the in-car temperature sensor.  There are many, many different systems used on these cars, depending on which of the many HVAC systems in your particular car - You'll just have to search the buyer's guide to find one that has the same functions as the original. I've always been able to find one close enough - even for much older cars, where the valve was cable operated.

Dick