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ZIPNZ

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Hi all,

I'm new to the forum, looks like a great community in here! I just purchased a somewhat restored '73 Mach 1 351c 2v (now has a Holley 4160 on stock 4v manifold and 4v open chamber heads) Ram Air, A/C, PB, PS, FMX, "Duraspark" single vacuum adv distributor, Red/Ginger std interior. Solid ride that spent it's entire life in SoCal and Vegas. Glad to be here! ::thumb::

I have a dilemma. Its seems that with some aspects of this car that instead of a true mechanic doing the work, a "parts installer" may have been under the hood at times instead. Problem being, that the vacuum system appears to be all wrong from what I can tell by doing some searches on this site. Therein lies my problem: I can't decipher exactly how the vacuum lines should be routed. For starters, the brake booster line is connected to the back of the carb base. The ram air is connected to the 3 prong vac tree on the back of the manifold, the distributor advance is connected to the front of the carb base plate, the PCV on driver's side valve cover is connected to the larger port on the front of the carb base plate, etc..

For starters, can someone tell me where (how) the vacuum lines are routed (from left to right) from the vacuum tree on the firewall?

Many thanks y'all!



 
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Hello and Welcome to the site. Looks like a nice car.

As far as the vacum lines you mentioned, they all sound like they are correct to me. Not sure what your exact set up is without some pics, but it sounds ok. Need a lot more info. What is giving you a problem? If it’s not running right could be a vacuum leak of some kind but need to know if it’s a stock set up or if you have a different carb and intake.

Anyway great looking ride and hope you have good luck with it!

 
Welcome,

Great looking car. Some pics of your engine showing the lines would be helpful. Also, you did not mention but what exhaust manifolds/headers do you have? The 351-2V manifolds would not fit the 4V heads.

 
Welcome,

Great looking car. Some pics of your engine showing the lines would be helpful. Also, you did not mention but what exhaust manifolds/headers do you have? The 351-2V manifolds would not fit the 4V heads.
Hi, thanks for the replies! Here's the info that I can recall (I'm currently at work)

1. I have the stock 351c 4v exhaust manifolds on the car

2. The vacuum line for the brake booster is connected to the back of the carb (I think that it supposed to be connected to the vac tree on the back of the manifold)

3. The PCV hose is connected to the front of the carb (I think it's supposed to connect to the back of the carb base)

4. I think the single vac advance line from the distributor is connected (correctly) to the front of the carb

I'll have to look and see where the ram air vac hose is connected to as well as the two vac lines on the 4 port tree on the firewall (2 of the ports are capped)

 
Last edited by a moderator:
Welcome from CT!

Due to the modified nature of the manifold and carb, the stock vacuum diagrams will be of very little use. Everything you describe sounds about right to me as well.

If there's anything in particular that you feel is incorrect, please post it up!

 
Welcome and YES it seems like you have a good handle on it (and yes the OTHER way isn't right)

I think if you take it one step at a time you will get correct.

1) get the booster signal done.

2) distributor (though right from carb base).....should be confirmed IF a correct vac advance. (Not a latter emissions retard)

The ram air is best to go by the diagrams and confirm both the dash pots and temp signals are working.

Mark

P.S. Nice when someone SHOWS they did their homework first !!

 
Welcome and YES it seems like you have a good handle on it (and yes the OTHER way isn't right)

I think if you take it one step at a time you will get correct.

1) get the booster signal done.

2) distributor (though right from carb base).....should be confirmed IF a correct vac advance.  (Not a latter emissions retard)

The ram air is best to go by the diagrams and confirm both the dash pots and temp signals are working.

Mark

P.S. Nice when someone SHOWS they did their homework first !!
Thanks everyone! Looks like I have a bit of homework to do! Oh, and another thing: the PO installed the Holley 4160 (square bore) directly onto the stock 4v intake (spread bore) with no spacer. I plan on installing a 1/2" phenolic square bore spacer so:

1. the secondaries will fully open (the secondary holes on the spread bore are slightly offset)





2. No heat soak

3. better drivability

With the ram air, a 1" spacer won't work due to hood clearance

 
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