have a 85 f159 4.9 and exhause check valve melted all my vacumme lines and instead of replacing them i wanted to remove all emissions crap.

My plan is to remove all unwanted wires and vacuume lines and put a carb on there from a 78 f150. Can this be done or do i have to get other parts, intake and exhaust manifold? i basically just want carb and motor no other stupid emission junk?

 

Depending on where you live, you need to check local emission laws to make sure you can take that stuff off 1st. If it's legal, you can take off the smog pump and attachments. Be sure to block the tube in the back of the intake. As far as your carb goes is your 85 TBI or is a carb also.

 

78 should still be jetted for smog, from what i can tell...you need a pre '75 carb and distributor...your dizzy is also curved for the emissions stuff. I'm going through the same process now, but i have a carter YFA carb and an '81 dizzy. It runs ok, but i think it could run better.

does your motor use O2 sensors? does it have a computer?

 

Also, do you have a feedback carb?

 

Since it's a 85 six, I bet it has the computer and everything. He will have to get another carb, and a new distributor and box to go with it.

If you have no vacuum line to the dist, then you have nothing to control the timing of the engine inside the dist, the computer did it all. If you take everything off, you need a dist that has the timing weights and vacuum advance on it to control the timing of the engine.

 

there is no vacuume line to the dist. just a connector. and no i dont have throttle body inj. carb only. so if i wanted to do this i would need a dist from a 75 or older plus carb. also whats a dizzy?

 

dizzy = distributor

 

You need a dizzy +carb + EEC ignition module. You might search this forum's
archives on "duraspark conversion," it's talked about fairly frequently here.

 

You will need a distributor with a vacuum advance, weights, and springs to control your timing.

If you decide to get a new distributor, consider our custom curved Duraspark Distributor built with our new Full Length Oil Impregnated Bronze Bushing. The full length bushing improves timing stability and spark scatter. If stock appearance is not an issue, take a look at our one piece D.U.I. Distributor. Whether you choose the Duraspark or the D.U.I., we curve each on a distributor machine based on your engine combination. Please see them at:

http://performancedistributors.com/forddistributors.htm

Also, there is now an excellent installation article on the D.U.I. Distributor on the Ford-Trucks.com site at:

https://www.ford-trucks.com/article/idx/0/358/article/DUI_Ignition_Installation_In_A_Ford_351W_V8.html

Ignition Lesson of the Month: Hystereses, the difference between the timing as the rpm and vacuum increases to the timing as rpm and vacuum decrease, needs to be kept to a minimum. A precise advance curve accomplishes this

 

if i buy a pre 75 carb and dizzy will i be ok. Also what if i just changed the carb and not the dist. and leave all wires in tact. the computer will still control timing correct. let me know what i need and where to get it

 

I would use a Carb from a 1980 F-350. These trucks were very smog light, due to the GVWR of the Vehicle at the time. It being a one ton. Etc... The only thing the 1980 F-350 carb should be calibrated for is a vacuum advance distributor, and PCV valve.

The base of some 70's and earlier carbs are different, and wont line up with the intake manifold. So be aware of this. Why I also Recomend the 1980 F-350. It should bolt right up.

 

I did a similar conversion on my 86 only I ran into some issues with the duraspark conversion so I ended up finding a new points style ignition. That is an easy setup but the spark isn't as strong as it would be with a duraspark. It works pretty well though. I'm saving my pennies for a DUI system. My truck still has a computer though it sits under the dash collecting dust.

 

Well i was plannin on goin down to the parts store and gettin a new carb. that info about the early 70's carbs is helpful thank you. I need a carb and a dizzy with vac advance? Correct. the dizzys they sell down the parts store there just reg "points style" right. what is the diff between duraspark and points style?

 

Duraspark is a breakerless Ignition system that consists of a Magnetic pickup in the distributor, and a Ignition Module, and coil.

The most Comon is Duraspark-II.

There are Duraspark-I and III components, but they are not compatible with DS-II.

The Duraspark-II is more reliable than points and require less maintanence.

Points system requires adjustment of the dwell when replacing components. Best done with a meter. The DSII does not require this adjustment.



What I would do is get everything for a 1980 F-350. Distributor, Coil, Carb and Blue Grommet Ignition Module. The only thing that you will have to get is a DS-II wiring harness out of a donor vehicle. The best thing is that the DS-II harness will plug right into the 1985's wiring if it hasn't been tampered with by a previous owner.

 

A Duraspark ignition system allows more voltage to flow through your ignition system, hence more spark at your plugs. Because of this factor, you can run wider plug gaps, burning your fuel more completley.

Point style ignition systems require you to run a ballast resistor to prevent from burning up your points. This reduces the voltage flowing through your ignition system to approximatley 9 or 10 volts, compared to the 14+ volts you can run through a Duraspark system.

As far as junkyard Durasparks are concerned, beware of their worn out upper bushing-they only have one. We utilize a full length oil impregnated bronze bushing in our Durasparks. This improves timing accuracy and it will be more durable for you. Junkyard Durasparks also can have worn out advance mechanisms.

"The Performance Distributors unit had no lateral shaft movement and spun freely. This is due to the full-length oil impregnated bronze bushing used during assembly. You won't find this in a stock replacement Duraspark unit. For curiosity sake, we tested the lateral shaft movement of a chain store replacement Duraspark distributor that was laying around the garage. The chain store replacement simply had mediocre tolerances." "Custom Curved Ford Duraspark Distributors," FordMuscle.com, January 2007.

http://www.performancedistributors.c...stributors.htm