Topic: S code PVS thread

[mungus]

Hi, I need a new Ported Vacuum Switch for my 68 S code GT. Broke the top pipe off the old one. Bugger.

Strange thing is most of those listed have a 1/2 x 14 NPT thread, whereas mine has a  3/8 x 18 NPT thread.
Only NAPA lists a 3/8 switch. Every other source shows 1/2.

I?ve checked a spare S code motor I have and it also has a 3/8 threaded hole on the thermostat neck.
And likewise when I search for new necks on line, they appear to have a 3/8 NPT inch sized hole.

Can anyone advise? Are there 2 types? Only 1 part number seems to come up when I look.

BTW I see all but one offered, have plastic upper sections. And that one looks to be 1/2 inch, and got a bad review at NPD. Temperature switching was way off apparently. (pictures below). Does anyone make a metal one a la OEM?

[jwc66k]

Did you look in this forum's library? There are links to "Ford Car Parts" (aka the infamous MPC), 75 ed, that should give you the Ford Service Stock Number, and possibly why the fitting sizes are different. Using the service number in your favorite search engine should give you some sources.
Jim

[J_Speegle]

Pretty easy to get an original, test it and restore one. Can't recall the temperatures needed for "switch over" point but with hot water and a couple of tube you can test if it seals and then opens at higher temps. Also using an original gives you the opportunity of having one that is more original than a replacement, correct original materials and even an appropriate date for your engine.

On another front are we certain we have an original thermostat housing?  Sorry I don't have a PVS here at my desk to measure at the moment