Topic: Canadian - 390 GT - PCV and emission systems

[Vince22]

Hi everyone,

I have a 390 GT 1968 with a 4-speed transmission, a brake booster and no A/C (8R02S160056 / 63A T 2A 04E B7 7 5).
I would like to install the PCV system and be compliant with the original configuration.
Note: I have a 67 air cleaner.

Today,I have an aftermarket carb (Holley CFM 600 -4776-2) without fuel inlet on the driver side.
I will fix it, buying a FUEL BOWL KIT Holley 134-108 and a Ford Style Trans Line (long) Quick Fuel 34-166QFT.

And today, on the carburettor side:

• The time spark vacuum source is directed connected to the distributor advance (note: it is a single diaphragm distributor.
• Then the Power Brake port is connected to the PCV valve / elbow (on the passenger side)
• And the PCV port is capped

Then the brake booster vacuum line is connected to the PCV intake fitting.
And as you can see on the attached picture, it is not the original configuration

And I do not have:

• the PCV tube and the large rear brass intake fitting (there is only a bolt…).
• the distributor vacuum control valve. In fact I do not have anything on my thermostat housing.
• the thermactor system (but I do not want to re-install it - at least not for now.

So I will buy the PCV valve (C7OZ-6A666-A), the PCV Valve adaptor (C7OZ-6A796-A), the hose and clamps, the PCV tube (C6OZ-6758-A), the PCV intakes fitting (C8OZ-9A474–A, C8OZ-9A474-B, C7AZ-9A474-A).
But I see two outlets on the C8OZ-9A474-B and two outlets on C7AZ-9A474-A.
I imagine that some should be connected to the carburetor (time spark vacuum source, power Brake port and the PCV port) and some to the distributor vacuum control valve.

So my questions are:

• is the distributor vacuum control valve mandatory?
• is a single diaphragm distributor correct for my mustang?
• how should I connect the outlets of the C8OZ-9A474-B and the C7AZ-9A474-A?

[Keith Stem]

This is a picture of a 68 390 PVC system from Mansfield Mustang, hope this helps.

[RoyceP]

1. is the distributor vacuum control valve mandatory? No but it does provide a way to increase engine idle RPM / fan speed if the engine overheats
2. is a single diaphragm distributor correct for my mustang? No it was originally a dual vacuum advance. You can keep the single advance and just connect it to the ported carburetor vacuum connection to eliminate the thermostatically controlled vacuum valve.
3. how should I connect the outlets of the C8OZ-9A474-B and the C7AZ-9A474-A? The U - tube connects them to one another.

[J_Speegle]

First welcome to the site. Hope you find the information and support here helpful in your concourse related endeavours

I have a 390 GT 1968 with a 4-speed transmission, a brake booster and no A/C (8R02S160056 : 63A T 2A 04E B7 7 5).
I would like to install the PCV system and be compliant with the original configuration.
Note: I have a 67 air cleaner.............

Not even getting into all the different versions of the 67 air cleaner it will obviously look out of place plus may mean that other parts of the emission system will be eliminated or not work as designed depending on the air cleaner base your using

And I do not have:

• the PCV tube and the large rear brass intake fitting (there is only a bolt…).
• the distributor vacuum control valve. In fact I do not have anything on my thermostat housing.
• the thermactor system (but I do not want to re-install it - at least not for now.

So my questions are:

• is the distributor vacuum control valve mandatory?

Mandatory for what? Given our focus here the answer would be yes since that is the way the car originally was equipped. But will it basically work without one? Many owners have rerouted around them  or removed them and the vacuum hoses and had well running cars.  In many areas removing and not using is a modification of the emission systems which is against the law if it ever comes up. So in that way it is mandatory

So my questions are:

• is a single diaphragm distributor correct for my mustang?

If your not going back factory why care? And since your not planning on using a PVS (ported vacuum switch how would you control a dual diaphragm distributor advance? It will work

So my questions are:

• how should I connect the outlets of the C8OZ-9A474-B and the C7AZ-9A474-A?

You don't have to but by joining out/balancing the vacuum between the two source is a better idea over all. Lots of aftermarket and other engines only use a single source. They can be joined by using rubber hoses and a T or you can use parts used on stock cars but be aware that the preformed pipe is shaped differently depending on application

Left to right. 390 - 428CJ  - 428 PI





Moving this over to the lounge area since its more about modifications than originality   As has been our practice over the years

[Vince22]

1. is the distributor vacuum control valve mandatory? No but it does provide a way to increase engine idle RPM / fan speed if the engine overheats
2. is a single diaphragm distributor correct for my mustang? No it was originally a dual vacuum advance. You can keep the single advance and just connect it to the ported carburetor vacuum connection to eliminate the thermostatically controlled vacuum valve.
3. how should I connect the outlets of the C8OZ-9A474-B and the C7AZ-9A474-A? The U - tube connects them to one another.

Indeed, today I have a single diaphragm distributor and no PVS and so the distributor is just connected to the ported carburetor vacuum connection.

To be compliant with the original configuration, I will start buying the PCV valve (C7OZ-6A666-A), the PCV Valve adaptor (C7OZ-6A796-A), the hose and clamps, the PCV tube (C6OZ-6758-A), the PCV intakes fitting (C8OZ-9A474–A, C8OZ-9A474-B, C7AZ-9A474-A) and the PVS (C8AZ-12091-A) with the hoses kit.
(note: I will keep the single diaphragm distributor for now and only purchase the Dual Diaphragm Distributor later).

So the question is, how should I connect the hoses between the PVS, the carb, the Single Diaphragm distributor, the PCV intake fittings…

I found the attached diagrams:

• the one for Dual Diaphragm Distributor is the one I should use later, when I will have purchase my Dual Diaphragm Distributor.
• but as I will keep the Singe Diaphragm Distributor for few months, I would like to use the other diagram.

But the questions are:

• as I have a 67 - early 68 air cleaner, I can not connect the blue stripe. Should I cap the outlet of the front intake manifold fitting or should I connect the blue strip somewhere else (carb ?)
• the yellow stripe is connected to the carburetor. Which port should be used ? (the time spark vacuum source ? the Power Brake port ? the PCV port ?) And the two other ports of the carb should just be capped ?
• as I do not have (yet) the air bypass valve (needed for the thermactor, I guess), should I just cap the outlet on the rear intake manifold fitting ?

[Vince22]

If your not going back factory why care? And since your not planning on using a PVS (ported vacuum switch how would you control a dual diaphragm distributor advance? It will work

Moving this over to the lounge area since its more about modifications than originality   As has been our practice over the years

Sorry if I was not clear.
Today the configuration of my car is not correct but I want to change it to be compliant with the original configuration.
So I am purchasing the parts to make the configuration of the carb, of the fuel line and of the PCV system compliant with the original configuration (and so I am planning to purchase a PVS too).
I just can not purchase the thermactor system for now (I will do it later, when I will have the money for it).

Note: I have a 67 air cleaner but it was the case on the early 68 390 (I think)

[RoyceP]

A 1968 390GT - even the earliest ones, from Job #1 - would have a typical 1968 390GT air cleaner assembly with snorkle and a round vacuum pull off door on the side of the air cleaner assembly.

The 1967 390GT air cleaner has dual screens, no vacuum pull off, and no snorkle. Totally different than 1968.

One of the vacuum diagrams that you selected is for an X code 390-2V. Again a totally different situation.

[krelboyne]

Vince, your DSO "B7" indicates Canada. 
In 1968, I believe that most of the exported 390-4V's to Canada did not have Thermactor smog systems, and they used 1967 air cleaners.
Are you making your car compliant for 1968 Canadian rules?

[Vince22]

Vince, your DSO "B7" indicates Canada. 
In 1968, I believe that most of the exported 390-4V's to Canada did not have Thermactor smog systems, and they used 1967 air cleaners.
Are you making your car compliant for 1968 Canadian rules?

Yes, I would like to make my car compliant for 1968 Canadian rules (in fact I would like to make my car compliant for its original rules).
Does the 390-4V's exported to Canada had a specific PCV system, had a PVS (C8AZ-12091-A) and had a dual diaphragm distributor?
Today, I do not have one any PCV tube, my thermostat housing does not have the hole and the thread for the PVS and I have a dual diaphragm distributor. So I would like to know which pieces I have to replace.

Do you have the Ignition vacuum schematic for the exported 390-4V's exported to Canada?

[RoyceP]

If your car was exported to Canada it would have not have had Thermactor and yes completely different shop manual and Master Parts Catalog too. And different cylinder heads and different air cleaner system. I don't have any documents for that - perhaps Scott does?

Yes, I would like to make my car compliant for 1968 Canadian rules (in fact I would like to make my car compliant for its original rules).
Does the 390-4V's exported to Canada had a specific PCV system, had a PVS (C8AZ-12091-A) and had a dual diaphragm distributor?
Today, I do not have one any PCV tube, my thermostat housing does not have the hole and the thread for the PVS and I have a dual diaphragm distributor. So I would like to know which pieces I have to replace.

Do you have the Ignition vacuum schematic for the exported 390-4V's exported to Canada?

[krelboyne]

I cannot find anything for this application.
My Canada 1968 introduction book indicates that Thermactor smog systems were planned for high performance engines (Holley equipped).

[krelboyne]

I think that it is possible that for 1968 S codes, Canada cars basically used the 1967 S code open emissions system. Not positive, but pretty sure that the IMCO system was not used.

[Vince22]

I cannot find anything for this application.
My Canada 1968 introduction book indicates that Thermactor smog systems were planned for high performance engines (Holley equipped).

Thank you Scott.

So you do not know what is the original configuration (PCV tube and rear fitting or not? PVS (C8AZ-12091-A) or not? Single or Dual Diaphragm distributor?) and you do not have the Ignition Vacuum Schematic for 390-4V's exported to Canada. Correct?

Do you know where I can find this information ?

[krelboyne]

The metal PCV transfer tube was used on most 390-4V engines since 1966 in the US. I do not know about Canada though.
Found a picture on my GT/CS forum of a 1968 S code Mustang from Canada. The Marti Report indicates "Non- Emissions System" in the options.
Does your engine look roughly the engine in the photo?  Google is your friend for the 1968 Canada vacuum routing. It likely looks the same or close to the 1967 S code non-California emissions.

[J_Speegle]

Sorry if I was not clear.
Today the configuration of my car is not correct but I want to change it to be compliant with the original configuration.
So I am purchasing the parts to make the configuration of the carb, of the fuel line and of the PCV system compliant with the original configuration (and so I am planning to purchase a PVS too).
I just can not purchase the thermactor system for now (I will do it later, when I will have the money for it).

Note: I have a 67 air cleaner but it was the case on the early 68 390 (I think)

Thanks for updating your intent. Originally with your questions it appeared that you were interested in not installing factory equipment and listed a number of non-factory items you planned on using/installing.  Will move the thread back to the 68 section.


As for the title -  since we now know the Canadian delivery that will get changed so that others with US delivered cars hopefully will not get confused between the discussion here and their needs.