Topic: 1967 4 speed, should I have a dual diaphragm VAC?

[mikelj5S230]

I am looking at my newly acquired '67 390 4 speed, and I see just a single diaphragm VAC, routed to the ported vacuum on the carb.  My thermostat housing is not correct, as it should have a threaded fitting for a vacuum control valve, I think.  Did the '67 4 speeds have a dual diaphragm VAC with one side hooked to that valve in the thermostat housing?  Thanks for any info.

[J_Speegle]

Guessing that your car is not a Thermactor car since you didn't list it


This chart (scanned from a Ford document) should help

............. Did the '67 4 speeds have a dual diaphragm VAC with one side hooked to that valve in the thermostat housing? 

According to the charts and the pictures I have of 67 S codes - no. Single diaphragm attached to the passenger side of the carburtator at the metering block. To the square brass elbow

[TLea]

+1. Only on Thermactor

[mikelj5S230]

Thanks guys, no, this is not a thermactor car (Chicago DSO and not listed on build sheet or Marti), I should have mentioned that. 

[Bob Gaines]

I am looking at my newly acquired '67 390 4 speed, and I see just a single diaphragm VAC, routed to the ported vacuum on the carb.  My thermostat housing is not correct, as it should have a threaded fitting for a vacuum control valve, I think.  Did the '67 4 speeds have a dual diaphragm VAC with one side hooked to that valve in the thermostat housing?  Thanks for any info.

No your thermostat housing should not have threaded fitting .It should be a one year only C7AE marked unit not C5 like what you have .It is also used on the 67 GT500 . it has a physical different appearance not just a number change . Look on the Mansfield site for a pic.  Does anyone have  distributor Tim's contact info handy ?    The single port vac diaphragm on your dist is the incorrect because of the style not because it is a single port unit.

[carlite65]

http://www.428cobrajetcars.com   but looks like the site is down.

[mikelj5S230]

No your thermostat housing should not have threaded fitting .It should be a one year only C7AE marked unit not C5 like what you have .It is also used on the 67 GT500 . it has a physical different appearance not just a number change . Look on the Mansfield site for a pic.  Does anyone have  distributor Tim's contact info handy ?    The single port vac diaphragm on your dist is the incorrect because of the style not because it is a single port unit.

Thanks Bob, I have seen a thermostat housing that has the cast bulge on the side of it, but not tapped and threaded for the eventual distributor vacuum control valve, like this one but this says late '67 so has a C8 part number? 
http://www.ebay.com/itm/151324175426?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
. 
I think I am looking for a VAC that has the threaded nipple that fits into it for the vacuum line, right?

[J_Speegle]

......... The single port vac diaphragm on your dist is the incorrect because of the style not because it is a single port unit.

+1 

Like the left example - not the right. Ignore the arrows - picture was made to illustrate some other details and just handy 




Mike - I guess you have checked the engineering number on your dist already just in case

[mikelj5S230]

I haven't checked it yet, but will, where would I find the number?

[J_Speegle]

I haven't checked it yet, but will, where would I find the number?

Red arrow - engineering number (generic example shown)

Green arrow - date code

[mikelj5S230]

OK, got it, but not real clear, here is what I think it says:

C7AF (maybe OF? not real clear) 12127 (clear) AA (clear)

Date code:  very faint stamp, but looks like:  6M26 (could be 28)

[Bob Gaines]

Thanks Bob, I have seen a thermostat housing that has the cast bulge on the side of it, but not tapped and threaded for the eventual distributor vacuum control valve, like this one but this says late '67 so has a C8 part number? 
http://www.ebay.com/itm/151324175426?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
. 
I think I am looking for a VAC that has the threaded nipple that fits into it for the vacuum line, right?

No that is a 68 truck thermostat. Vac pod like Jeffs single port picture.

[Bob Gaines]

The BB thermostat housing is very hard to find. If you can't find one PM me because I may have one as it is a often missing detail piece on a 67 GT500 also.

[mikelj5S230]

OK, got it, but not real clear, here is what I think it says:

C7AF (maybe OF? not real clear) 12127 (clear) AA (clear)

Date code:  very faint stamp, but looks like:  6M26 (could be 28)

In researching that engineering number (though the date looks OK), it appears to be not correct for my car, as it decodes as a 390 2V C6 application.  So guess I need to start a search for the correct distributor as well.

[mikelj5S230]

The BB thermostat housing is very hard to find. If you can't find one PM me because I may have one as it is a often missing detail piece on a 67 GT500 also.

Finally found one, thanks Bob!