Full time vacuum 69 427/400

[Grahame M.]

Hi Everyone,

I know this has been asked and answered many time in this forum after reviewing many posts on the subject. I just can't seem to find any posts with clear pictures or diagrams of where the 3x2 carb vac hoses go and in particular the cut in for full vacuum?

Any help would be much appreciated and if anyone can link me to a thread for this information i'd be forever grateful.

Many thanks
Grahame

[Joe L.]

Re: Full time vacuum 69 427/400

Hi Everyone,

I know this has been asked and answered many time in this forum after reviewing many posts on the subject. I just can't seem to find any posts with clear pictures or diagrams of where the 3x2 carb vac hoses go and in particular the cut in for full vacuum?

Any help would be much appreciated and if anyone can link me to a thread for this information i'd be forever grateful.

Many thanks
Grahame

Grahame------


You can tee into the line that goes to the choke unloader on the center carb.

[Grahame M.]

Re: Full time vacuum 69 427/400

Joe,

Thanks for the quick response, can this also be called the choke pull-off?

[Duke W.]

Re: Full time vacuum 69 427/400

Yes... also called choke vacuum break. Take off the existing hose and save. Buy a couple of feet of 1/8" tubing and a tee, and build a new harness.

I don't know the VAC specs for your engine, but make sure it passes the Two-Inch Rule, idling in neutral if a manual trans and Drive if an automatic If not buy a VAC that does.

After completing the change go through the idle speed/mixture adjustment procedure, and you will also need to reset the fast idle speed to spec.

Duke

[Jeffrey S.]

Re: Full time vacuum 69 427/400

If the smog equipment is there, couldn't you also "T" of of that vacuum line?
Jeff

[Grahame M.]

Re: Full time vacuum 69 427/400

Thanks Duke,

i have all your (and others ) articles and threads saved on this subject so hopefully will complete this update soon. I have an original refurbed clutch and 7 blade fan, new water pump, hoses and a Dewitts direct fit aluminium radiator and new seals, so i'm hoping this will fix overheating problem. From the threads i have it seems like it will.

Once i get it back running i'll recheck vacuum (was at between15-16", CR around 180 all cylinders) prior to garaging. The only issue i had in this area was the vac gauge needle fluctuated back and forth slightly but this is probably a question for another day.

Thank you again for everyones comments, very much appreciated as always.

Cheers
Grahame

[Joe L.]

Re: Full time vacuum 69 427/400

If the smog equipment is there, couldn't you also "T" of of that vacuum line?
Jeff

Jeff------


I believe the vacuum source for the diverter valve is ported vacuum.

[Duke W.]

Re: Full time vacuum 69 427/400

The diverter valve should be full time vacuum, but it takes about 20" Hg to open it. The valve's purpose is to divert injected air through the muffler to the atmosphere when the throttle is lifted to avoid exhaust afterfire.


Duke