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6TSeven, foolishly, I sold my tripower FE intake. So I can't run out and look at it and tell you where to hook up. But I CAN tell you that vacuum advance gives more fuel economy with zero horsepower penalty. I'd be finding a way to hook it up, if it were mine. And if I may ask, where do you live ? I wonder everyday where mine went. LSG
 

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My setup, I was told by engine builder that distributor needs "ported vacuum", not just any vacuum off the back. If Ford made specific parts (dual point distributor, mech advance) listed just for this setup, then that's what I went for.
With a chassis tune on a dyno @ ~ 425 foot lbs torque with this setup, I'm ok with. As for fuel economy, I've driven from Carlisle Ford Nationals in PA with friends back to southern NH and got ~ 15 mpg, that's fine by me. With an FE engine fuel economy not my worry. With amild cam spec'd, aluminum hds, SCJ exhaust manifolds, manual trans, it does ok.

I bought this setup off a good friend who had it a long time on his 68 390 FB. But was running like crap because carbs junk (warped). Had to replace with 3 new Holley's from Carl's Ford Power parts.
 

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67GT, tell me who is this engine builder who thinks your engine needs ported ? I want to hunt him down and, umm, educate him. I recently retired from an engine building shop, and went to school to learn things, and can tell you for a fact, there is no engine combination that 'needs' ported vacuum. Some engines had it, but the ported vacuum scheme was only thought up to increase temperature at idle. It was an early emissions era idea to burn off hydrocarbons. Noone, repeat, NOONE, 'needs' this. A correctly leaned idle mixture, with full manifold vacuum, is what 99% of us should run. The reason we need manifold vacuum at the dizzy is because during street driving, the vacuum canister advances timing in a way that the centrifugal just cannot be programmed to match. I realize some cars, like a 289 hipo, came with no vacuum can. This wasn't because the engine wouldn't get better fuel economy with one, or the engine didn't 'need' it, it was strictly because the manufacturer was trying to be cheap. The ONLY guys that can't really make use of vacuum advance are cars that 100% drag strip, EVERYBODY else should have it. The problem you have, is that there are not so many guys around who know how to correctly set it up any more. What your builder was really telling you, is that he doesn't understand how vacuum advance works, and he doesn't know how to do it. You CAN run with that intake, and the 390 in a Mustang can give you 17~18 mpg, with full vacuum and running center carb only on cruise. BTDT. Damn ! I wish I'd kept that ! I kept a single 4 and a dual plane, dual 4, for the FE. Anyway, if you're getting 425 lbs-ft, you're running well. But if you wanted to squeeze a couple more mpgs out of her, you could.

Don, the dual point idea was to allow more time for coil saturation at higher rpms. Rpms higher than most of us use on the street anyway. And the duals are kinda fussy to set up, one set makes, the other set breaks, the connection to the coil. I'd run a DuraSpark, or a Pertronix, or a single point setup. The DuraSpark will give more coil saturation, always and at any rpm, than the dual point could ever hope to maintain. And the points are about 2 & 1/2 amps, the DuraSpark is 4~5 amps, which means more power to the coil and more spark at the plugs. DuraSpark is my first choice of distributor if I can get one. LSG
 

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67GT, tell me who is this engine builder who thinks your engine needs ported ? I want to hunt him down and, umm, educate him. I recently retired from an engine building shop, and went to school to learn things, and can tell you for a fact, there is no engine combination that 'needs' ported vacuum. Some engines had it, but the ported vacuum scheme was only thought up to increase temperature at idle. It was an early emissions era idea to burn off hydrocarbons. Noone, repeat, NOONE, 'needs' this. A correctly leaned idle mixture, with full manifold vacuum, is what 99% of us should run. The reason we need manifold vacuum at the dizzy is because during street driving, the vacuum canister advances timing in a way that the centrifugal just cannot be programmed to match. I realize some cars, like a 289 hipo, came with no vacuum can. This wasn't because the engine wouldn't get better fuel economy with one, or the engine didn't 'need' it, it was strictly because the manufacturer was trying to be cheap. The ONLY guys that can't really make use of vacuum advance are cars that 100% drag strip, EVERYBODY else should have it. The problem you have, is that there are not so many guys around who know how to correctly set it up any more. What your builder was really telling you, is that he doesn't understand how vacuum advance works, and he doesn't know how to do it. You CAN run with that intake, and the 390 in a Mustang can give you 17~18 mpg, with full vacuum and running center carb only on cruise. BTDT. Damn ! I wish I'd kept that ! I kept a single 4 and a dual plane, dual 4, for the FE. Anyway, if you're getting 425 lbs-ft, you're running well. But if you wanted to squeeze a couple more mpgs out of her, you could.

Don, the dual point idea was to allow more time for coil saturation at higher rpms. Rpms higher than most of us use on the street anyway. And the duals are kinda fussy to set up, one set makes, the other set breaks, the connection to the coil. I'd run a DuraSpark, or a Pertronix, or a single point setup. The DuraSpark will give more coil saturation, always and at any rpm, than the dual point could ever hope to maintain. And the points are about 2 & 1/2 amps, the DuraSpark is 4~5 amps, which means more power to the coil and more spark at the plugs. DuraSpark is my first choice of distributor if I can get one. LSG
^^^+++ The idea of ported vacuum advance was an emissions solution ONLY. When you're driving down the road with a partial throttle and high vacuum your engine runs better with more advanced spark timing. That's what vacuum advance does. My 390 has a factory vacuum switch that changes the vacuum advance from port to manifold above 220 for just that reason - it then runs more efficiently which increases the RPMs which increases both the water flow and fan/air flow to lower the engine temporature.
 

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CJM, yes, LOTS of our engines came with a DVCV. Whenever I encounter them, I leave them in place and run the vacuum line from the can to full manifold vacuum. The 'ported' stuff is just dumb. LSG
 

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LSG, appreciate the in depth input.
Now when my orig engine was rebuilt, it was ~ 18 years ago. At that time I had engine put together with the stock rebuilt dist, (which at the time builder (R&L Engines) wanted it to have "full advance" come on at 2,700 rpm). I have pics of my engine going into car with dist w/vacuum advance on it. I know engine sent to separate race engine shop (R&R Engines) to have it engine dyno'd before given to me.
Once in car and running, at some point short time later it went to a chassis dyno shop, "Performance Dyno" to have it tuned, is where I got the 425 foot lbs torque reading.
After a short time on the road, easy driving, a rocker shaft snapped off at end at rocker stand. Engine friends recommended I use Harland Sharp shafts & and screw in studs. Then our club President, a certified Master Mechanic helped me set up lifter adjustments.
What I don't remember is why I felt it wasn't running well, and who suggested I switch to "ported vacuum". This all many years ago now. It since runs very well, weekend driver so happy with it. My goal then was "show & some go".

Thanks for reading
 
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