Topic: 70 Mach 1 351c Ported Vacuum Switch

[pjmach1]

Howdy,
1st Time Posting here..  Building 70 M1 Sanjose built. 351c 4V 4sp Shaker.. Well optioned build..

My question is.. on equipped 351c w/Dist. Vacuum Control Valve/ Ported Vac. Switch.  is this unit located on the Water Pump or engine block..

Appreciate your help.. Will be back for more of your insight again.

thank you

Pete

[J_Speegle]

First welcome to the site - hope you find it helpful


If its so equipped (maker sure your car used them) it would be in the water pump below the uppermost heater connection





Sorry for the poor picture - not an easy piece to get a clear picture - unless your taking it for that specific reason

[SCJSTU]

Pete,
they are also date coded.....seems like they were made in batches.....
I have a couple spares if you need one......just let me know your build date


PS.....it helps if in your signature you put your build date,plant,options so folks can see and answer questions specfic to your car....

thanks, Stuart

[J_Speegle]

Ford the "D0AZ" version there is a dated and a undated version.

If you look at the example below the design on the side is different (though same part number) likely IMHO a different supplier

[J_Speegle]

Ford the "D0AZ" version there is a dated and a undated version.

If you look at the example below the design on the side is different (though same part number) likely IMHO a different supplier or its always possible an early and later version

[Andrew@MagMustangs]

Wow, thanks for posting those Photos Jeff. I don't recall ever seeing one like pictured on the RH side. I personally think it is most likely a different supplier, but that is just personal theory.

 As far as being an early or late version, the one on LH side of your pictures is in the same configuration as the earlier C8AE-A version with the (PAT PEND) symbol on top. I have had a lot of 1970 cars and IIRC they all had the LH valve. Even a 1973 I did recently had that same configuration. I'm not sure how long this same DVCV was used after 1973, I don't get into those years of cars, but I guess the RH Valve could possibly be a really late version? Used after 73?

From what I am aware of there are 2 known suppliers of the commonly seen valve pictured on LH side. In the Date code the -H- or a -K- designates the manufacturer of the valve. The -H- is assumed to be Holley Corporation. No solid evidence on the -K- manufacturer, although I have speculated it might relate to Kelsey Hayes. Andrew

[SCJSTU]

Jeff,
do you think the undated/unmarked ones are service replacemnets?

[J_Speegle]

Jeff,
do you think the undated/unmarked ones are service replacements?

We have nothing (at this point) to suggest that IMHO - Not sure why the dating (and supplier) would not be as important on a service replacement as on an earlier version if that were so. 

Have one stamped version marked 9-H-01 not sure what that indicates. Unfortunately I didn't write down where each one I have was found