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Other than nitrous, that is... I am looking to up the HP of my '69 351 4V and I want to know the best way to do it. Headers? Which direction should I go with this thing to up the HP?
 

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Same question for me, except mine is a 351 2V, I need to burn some SA roads up. We've got a big wheels show coming up in September and as I have so far only identified 2 other cougars in the country I want ours to be the cewlest, the meanest, and if not the fastest, definitely the noisiest. We don't really have noise and emmission controls here, if we did, half the taxi's would be off the road.
 

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I'm only making a few mods on mine as soon as I get some extra cash. I have a 351-2V and, with the advice of the many members here, I have decided on:
Edlebrook Performer Intake to convert to 4 barrel carb, Headers, dual exhaust with Flowmasters and update the ignition. The engine is still strong with 50,000 miles so I'll wait till it dies before I make any stronger mods. I think those changes will give me the added horsepower I'm looking for without sacrificing the every day drivabilty. But of course, the 351C is capable of some big horses with more changes. It's just a matter of how much horsepower you want, and how much money you want to spend.
 

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I've got an Edelbroke Performer intake, but not sure about the convert to 4 barrel carb, explain. What are headers?
I have duel exhausts but not sure if they are freeflow or not.
Upgrade the ignition, explain please. I have a holley 600cfm carb, 2 barrel I guess.
 

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its a 1850-4, so maybe a 4 barrel
 

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Dayle, you do have a 4 barrel on there. Next you should get dual exhaust put on, with headers or the stock exhaust manifolds, and upgrade the ignition to electronic. Any aftermarket conversion kit is good for street use.
For a nasty, but streetable 351 W or C, choices would be, alum. 4 barrel intake and 600-650cfm vac. sec. carb (remember streetable/fuel economy), headers (or duals), electronic igntion, and 3.25 to 3.50 gears in the rear end (posi not neccesary). That will definately wake the car up, and be a pleasure to drive. Anything more and you need to upgrade cam, heads, tranny,etc.

Rick
 

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72cat

Your Holley 1850 is a four-barrel carburetor. Somewhere along the way, someone replaced your stock 2V setup with an aftermarket 4-barrel intake and carb. (by the way, the 'V' in the Ford nomenclature denotes Venturi. Venturis are another term for 'barrels'.) The confusion comes with Cleveland engines in that they produced different cylinder heads for the 2- and 4-barrel engines. The 4-barrel heads have much larger, free-breathing intake and exhaust ports and, for 1970-72, larger valves. That is why I have tried repeatedly to distinguish between your 2V motor with the aftermarket four-barrel intake and carb from the true 351C-4V. Big difference!

Headers are tubular exhaust manifolds. They are made from conventional exhaust tubing, with separate tubes for each exhaust port. They generally tie together the four tubes some 30 inches from the exhaust port under the front seat footpan. They are free-flowing, meaning there are no restrictive bends like you would find in a conventional cast-iron exhaust manifold. Headers are used when you want to increase the air (exhaust) flow out of the engine. Some factory Ford engines in the mid 1960s had free-flowing cast iron exhaust manifolds, with gentle bends and larger passages. These are sometimes referred to as cast iron headers. They were used on the FE series of engines of higher output like the 427. Some small block Ford engines also got free-flowing manifolds. Generally, they are found on the 289 'Hipo' or high-performance engine, also of the mid-1960s era.

Upgraded ignition: One that will provide a hotter, more consistant spark to the spark plugs at high rpm. The stock ignition system was designed to work well under 4500rpm. Above that rpm the strength of the spark tends to get weaker. Also, sometimes the spring on the points isn't strong enough for the follower to stay in contact with the distributor eccentric. When that happens, the points are said to 'float' and the time the coil has to recharge between spark impulses is even less that what the rpm would suggest, making for a weaker spark.

Free-flow exhaust: Upgrading your exhaust system from single to dual exhaust will generally increase the flow capacity of the exhaust. (i.e. one tube flows less than two of the same size). The gentler and less number of bends, larger diameter tubing, less restrictive flow mufflers will help an exhaust flow better. Blow through a kinked-up drinking straw versus blowing through two straight straws will get this point across to you.
 

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3:55 GEAR or 4:11 or 4:56
 

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pat said:
Headers are definitly a great way to get (relatively) cheap horse power. They are a bit of a pain to put in, but in my opion, they're worth it:D
However, when going to headers, you will be going from single exhaust to dual exhaust, which is an additional expense. Since you already have a 4v that really leaves only a cam. you will probably get an equal boost in increased HP with either, and a good cam is cheaper than headers and duals. I suggest you do both for a real leap in HP.
 

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Before changing the bump stick I would at least put on duals - preferably with headers, but they are not necessary. If you are going to put in a hotter cam you need to make sure that you have a good induction/exhaust system to reap the benefits, otherwise you're going to be disapponted.
My opinion of biggest "bolt-on" bangs for the bucks:
1. Electronic igniition
2. Dual exhaust, preferably with headers. Not too big or you can over breathe the engine - 351C-4v with the big mucking valves and ports did that. Loses all the low end.
3. Induction, be it a free breathing air breather, cold air box or preferably a 4V carb. Remember, there is a lot that can be done to improve your induction system without spending the bucks for 4V intake and carb.
4. Cam

Changing your rearend ratio with give you quicker acceleration and may feel like more HP but there is no HP gain.
 

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I've got a 351-2v with dual exhaust. I'm not sure whether they're free flow or not... were they aftermarket or did it come from Ford like this?

Does this mean I could just pop headers in there with no problems? Bolt-on and drive?

It sounds like I will go the headers route. Anyone have any good leads as to which vendors work best? Personal experiences with any of these projects?

Also, I suppose an obvious performance boost would be upgrade to a decent 4 barrel carb?

Sly
 

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Thegamebrain, if you install headers, you will have to modify or replace your existing dual exhaust setup since the headers will most likely go closer to the ground than your stock exhaust manifolds.

The venturi size on the 2V is actually bigger than the 4V primaries, so you will get more air flow at low rpms. The advantage of the 4V is when all 4 "barrels" open you get more air flow. As well, since the primary bore size is smaller, there will be some fuel savings at low rpms. It all depends on the type of driving that you do!;)
 

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So what you're saying is if I switch headers, I have to replace my current exhaust setup? For once, I wish it was all rusted out... would make it an easier decision, lol.

Thanks, I think I knew that about the 2/4V difference, but had totally forgotten. Looks like I'll have to rethink this then.

It's just that 250 HP seems to fall a bit short for a car of this magnitude. Gotta get this cat at least over 300

Sly
 

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Discussion Starter #16
What is the stock HP for some of these cars? On my '69 351 4V, it was my understanding that I had somewhere in the range of 300HP stock...?
 

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back in the late 70s my friend had a 70 cougar 351w 2v, all we did was put a 3:55 gear out of a 72 model in it and he was blowing away all those alum. intake 4v, header, shift kit cars. the rear wheel hp went up and it gave it much better torque multiplication. But the gas mileage went out the window.
 

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Okay the two biggest things you can add for better HP and for under 1000.00 is headers first and foremost and second is roller rockers. Now of course as already stated if you have only one pipe you will need to conver to duals so this will add expense as well. but these two things and the most hp for the buck this is without cam change carb change or any oter bolt ons. now if you want to go that little extra pull your heads and port and flow and machine for big valves another 500.00 or since you already have a 4v keep what you got most people over carb their cars anyhow. A big carb means very little on the street except sucking more gas than it needs. Most appplications take only a 600 to 650 carb and you will have a great motor set up. Add the shift kit to the FMX and 355 gears and you will burn up the road and get decent milage and ride.
 
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