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1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

1981 351M Vacuum lines

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Old Feb 6, 2019 | 09:31 AM
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1981 351M Vacuum lines

I recently picked up this '81 and got under the hood. I noticed it's been de-smogged and looks like a lot of vacuum lines are missing. Does anyone have one that could post some pictures of the lines running from the thermostat housing, and any other that might be important? It would be a big help after I do a rebuild of the motor and C6 trans. I'll get a few pictures up myself in the next hour or so.
 
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Old Feb 6, 2019 | 09:57 AM
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You should have a diagram on the radiator support for your engine vacuum lines.
 
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Old Feb 6, 2019 | 02:19 PM
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Originally Posted by Franklin2
You should have a diagram on the radiator support for your engine vacuum lines.
I do, but it's not overly helpful with how much is missing. I don't have a whole lot to go off besides vacuum advance.
 
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Old Feb 6, 2019 | 03:54 PM
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Originally Posted by 351Mainer
I do, but it's not overly helpful with how much is missing. I don't have a whole lot to go off besides vacuum advance.
Ok if you don't need all that hooked up to pass smog test then don't worry of hoses missing and some ports left open like the ones on the T stat housing as they did go to things but if you don't have a vacuum supply going to it then no worry.

You only need about 3 hoses:
1- hose from carb to the dist. for vacuum advance.
2- hose to power brake booster
3- hose to the HVAC control if you have factory AC
So if you don't have AC or power brakes you would only have 1 hose.

BTW my 81 with a 300 six only has 3 vacuum hoses, it has factory AC & power brakes.
Dave ----
 
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Old Feb 6, 2019 | 03:55 PM
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Originally Posted by 351Mainer
I recently picked up this '81 and got under the hood. I noticed it's been de-smogged and looks like a lot of vacuum lines are missing. Does anyone have one that could post some pictures of the lines running from the thermostat housing, and any other that might be important? It would be a big help after I do a rebuild of the motor and C6 trans. I'll get a few pictures up myself in the next hour or so.
Depends on what you mean by important. If it is needed for to meet smog visual inspection or pass smog a test then it is important. Otherwise it is not and the truck will run better and get better fuel economy with out it.
And being a 351M the best thing you could to it is source a 400 crank and convert it to a 400.
 
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Old Feb 6, 2019 | 05:03 PM
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If you need them hooked up, you will have to post a picture of the sticker, and good pictures of the carb and the engine compartment. There are people on here who can help you get most of it hooked back up.
 
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Old Feb 7, 2019 | 06:23 PM
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You should have a hose running to the trans modulator.
Mines also been desmogged so not much help. My sticker attached, but seems like you got this covered.


 
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Old Feb 7, 2019 | 07:14 PM
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Originally Posted by packagerjr
You should have a hose running to the trans modulator.
Mines also been desmogged so not much help. My sticker attached, but seems like you got this covered.
Good call on the trans vacuum
Dave ----

 
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Old Feb 7, 2019 | 07:50 PM
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Originally Posted by FuzzFace2
Good call on the trans vacuum
Dave ----
PCV hose too. Mine goes right to front of carb.
 
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