Where to find a heater control valve

How exacting are you being with this repair? If you require a valve that looks exactly like the factory original, you're going to be in for spending bigger money than if the goal is to get the system working again quickly and efficiently.

Your type of factory air system was used from '65-'72. The heater water valve through '70 (including your '65) has two vacuum hoses going to it: one to open the valve and one to close it. The water valve for '71 and '72 (and carried over into the new-type HVAC system for '73-up) had one vacuum hose; it was spring-loaded rather than having the "other side" vacuum hose. he pre-'71 type (and its vacuum pots, which are separate parts) have been unavailable for years, or very expensive when you can find them; a later-type (single vacuum hose) valve (this one) can easily be installed to get the system working just fine without spending a pile of money. This is a "vacuum closes" valve, so you hook up the hose that used to close your two-pot valve (the hose that has vacuum when the "MAX A/C" button is pushed). Cap the hose that used to open the 2-pot valve (has vacuum in positions other than "MAX A/C") and you're all done—system will work normally for a long time with this $10 repair.