I have a question for all the FE experts about heads. I have a 76 F150 that I am going to start restoring. It has a transplanted 72 390 in it. I'm kicking around the idea of a installing a factory tri-power set up when I rebuild the engine. Will the tri-power work with any FE heads or are there specific heads that I will need to get? Thanks for your help.

 

The factory Tri-power setups came on 390s and 406s in '61, '62 and '63. They will fit every head except the 427 high riser and 427 tunnel port.

They are realtively easy to set up if you are willingly to spend some time and it takes time becase you have 3 set of idle screws, etc.

They are hard to drive effectively because if you floor it you get a lot of carb ALL AT ONCE and most vehicles can't handle that at low RPM. Then the engine bogs or stalls and you are not a happy owner. This would be worse in a loaded truck. You did not ask for an opinion on this idea, but you would probably be much happier if you had a 4 BBl carb with vacuum secondaries.

Still it would be very different, so try it anyway! You can always remove it if you can't live with in.

Bob
'66 7 Litre, top loader, 3.25 Traction-lock, Sidewinder Intake, SCJ Exhaust
'88 F150 LWB 4x2, XLT Lariat, 302, 5 speed, 3.08
'99 Ranger, 4x2, 3.0, 5 speed, 3.73 posi

 

The tri-power intakes have larger intake ports than your heads. You will need some '66 or earlier heads in order for the ports to match.

Jason Kendrick
1970 F100 Custom 390/C6
1978 F150 Ranger Lariat Supercab 460/C6

 

the idle circuit is only on the center carb on a tri power setup. i built one with my uncle in 89. I had a fit trying to make it idle. my uncle came out and looked the engine over a few minutes and laughed at me. he had built TONS of Fe's over the years. he left me standing there looking dumb. so i followed him back in the house and asked what was so funny. he said to me ya idiot the idle circuit is on the center carb not the front one. when i swapped the fuel lines around it idled like a charm. he died a couple weeks later. i have never forgotten. i wish he were here now. i could use his help on my replica of his 65. 390 3 on the tree and 4.11's. i cant wait to get my truck to alabama so i can ride. i have the engine now i just need to get the truck here so i can install it. im gonna teach my sons as much as i can so we bleed ford blue at least for the next generation.

 

Just out of curiosity, I know nothing about three carb setups, but are you saying that the only carb that the fuel line is attached to is the center carb? or are you saying that the outside carbs don't have mixtre screws? Also why wouldn't the high riser manifold work? It's blatantly obvious the tunnel port wouldn't.

 

The High Rise ports are a much taller, 2.74 inches, than the 1.93 height the tri-power manifold was designed for. You probably could not get a good fit on the gaskets and matching the ports to smooth the air flow would be difficult if not impossible.

In other words, they would bolt in but would not work well even if you could get a good seal at the heads.

Bob
'66 7 Litre, top loader, 3.25 Traction-lock, Sidewinder Intake, SCJ Exhaust
'88 F150 LWB 4x2, XLT Lariat, 302, 5 speed, 3.08
'99 Ranger, 4x2, 3.0, 5 speed, 3.73 posi

 

The tri power is great!
Just like a double double pumper.
Give better fuel distrubtion than a single quad (at speed)

Just port match the heads if the dont fit spot on.

Tune the carbs and set up the progressive linkage.
(an extra spring lets you know where the secondaries are opening keep em closed for economy)

do it :^)

 

the end carbs on a tripower setup are just fuel dumpers. they open whenever you hit a certain point of travel. there are no idle circuits on the end carbs. they all have fuel lines connected. there is a certain way they have to be connected so that the center carb can provide idle speed. the end carbs dump fuel all at once. i have heard of progressive opening tripower setups but i have never seen one. the ones i have seen all run off the center carb for low speed and constant speed but when you jump on the throttle the end ones dump and it either bogs and recovers or IF and this is a big if its tuned correctly it takes off like a scalded dog.

 

Thanks for all the info on the carbs guys, but my original question is still somewhat unanswered. Bsprowl says my 72 heads will work with the factory tri-power but 390FE says I need 66 or earlier heads. Can anyone shed any more light on this. I'm thinking of going with the tri-power just to have something unique. I don't think to many people would expect to see a six pack under the hood of a truck.

 

By the book: Your '76 heads have 1.81 inches tall by 1.34 inches wide ports; the 390-406 HP engines had 2.34 tall by 1.28 wide ports; the manifold has 2.20 tall by 1.14 wide ports.

1. Measure what you have. Someone could have previously opened the ports on the intake manifold, etc, or the book could be wrong.

2. Take an intake manifold gasket and line it up on the heads and note where an intake port fits vertically on the gasket. Now take the gasket and do the same on the manifold. Compare the vertical port alignment. (I have taped a piece of paper across the port opening on the gasket and then punched a small hole at the top and bottom edges of the opening on the head then moved the gasket to the manifold and used the holes I made to see how well the manifold port lined up with the head.)

3. You can now decide if you think the ports can be matched by grinding or if they are grossly misaligned and won't work together. You might also compare how well the orginal intake ports lined up with the ports on the heads.

Since your are after horsepower consider switching your head to almost any passenger car model. The ports in your truck heads are designed for low rpm torque and not for horsepower.

Those that suggest the heads and manifold won't work well together are correct but then if your are after big horsepower you won't use the truck heads. I believe you can open the heads up enough smooth the air flow and use the intake manifold. It will not work nearly as well as using other heads.

Bob
'66 7 Litre, top loader, 3.25 Traction-lock, Sidewinder Intake, SCJ Exhaust
'88 F150 LWB 4x2, XLT Lariat, 302, 5 speed, 3.08
'99 Ranger, 4x2, 3.0, 5 speed, 3.73 posi

 

Hi 4Fords:
I realize this is quite a while after your inquiry re: the Tri-Power setup for your truck. I just logged on to this site and viewed your question and some of the responses. I was surprised at some of the views given. The Tripower will bolt right on, the port alignment may not be perfect, but it will work. As far as carb setup goes, for your application you can stagger the opening point for each carb with the mechanical linkage so that you can minimize the bogging. You may have some tinkering to get the throttle hooked up as well, I can't remember if your year of truck is linkage throttle or cable?
Forget about using High Riser parts on a 390, they will not work. The valve spacing on the heads is so large that the valve distance is actually greater than the bore diameter of your block and therefore the intake valves hit the cyinder wall. Also High Riser intake manifolds only fit High Riser Heads and will not interchange with any other heads. Tri-Power setups are quite good if you just tinker with them a little to understand how they work. Bolt it on and have some fun.
Hope this is of some help.