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How can I get better performances ? 351 2V
I'm quite happy with the performances of my 72 Grandé for everyday street cruising but I'd like to get "a bit more". Like many people, I wonder what is the "next step" to get a bit better perf Smile something like 300 HP would be great.

Engine is a '72 351C 2V. I'm currently using a Weiand intake in this and a 600 CFM Holley Carb.
Exhaust is the original one but I plan to get some Hooker headers and a new exhaust kit with Flowmaster mufflers.

I think my engine is tuned correctly because the car runs great and it's cool to drive. I'm doing 0-60 in 8 seconds.
What do you think is the next step to get some more power ? 4V heads ? 650 CFM carb ? Stroked engine ?
Here in France parts are much more expensive because of the shipping and taxes, and used parts are expensive too, so I don't want to do a mistake. I know there are tons of things to do to get better performances, but I don't want a racing car, just a bit more fun to drive Smile
Closed chamber 4V heads will boost your compression a full point but are costly and you'll end up putting in a cam, lifters,timing chain and gear while you'd have it apart. The 73 2v with the open chambers left a lot on the table horsepower/compression wise due to the emissions that started that year. Cost wise a larger cam and a good hot distributor/ignition set up will also be good. It depends on how much BETTER you're looking for.

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
What ratio gear set is in the differential now? Is the transmission and convertor stock? How important is gas mileage to you? The Hooker competition 2V headers are a good choice. Which high flow mufflers to select is more of a personal preference decision most of the time. I personally like the sound of something other than flowmasters. Assuming you have a 3.25:1 or numerically higher gear set, A cam lifters, timing chain set, and valve springs (and better rocker arms if the budget allows) would seem to be the next step. The stock Ford, multi-groove valves are notorious for breaking especially when the RPM range starts to climb. I would suggest a set of good single groove valves and keepers along with a high quality 3 angle valve job. Your new intake and carb would not be a good fit to the 4V heads and you would still need to buy all new valve train components. The 2V headers will not fit the 4V heads either. Based on what you have said you want and what you already have, I'd stay with the 2V heads and select a cam that is well matched to the total combination of parts you have ( compression, gear, convertor, intake, etc.). I'm glad to hear you are enjoying driving the car. Good Luck, Chuck
The above advice is good. You will get some additional performance with headers and exhaust. You will gain a little power (maybe) with an aftermarket ignition. You can improve your 0 to 60 times with a dual plane intake. Engine wise, there isn't much more to do except tune it. To get real performance improvement you will need to go with a different cam. This can be done with the engine in the car but it's easier if the engine is out. You can't go much bigger on your cam with out matching up the rest of the drive train and replacing the 1 piece ford valves. At some point you have to ask yourself if you want to go 'all in'? Replaceing the valves means pulling the heads and getting valve work done. So do you put money into 2v open chamber heads or go 'all in' and get some 4v or aftermarket heads. The cost goes up fast.

Additionally, if you get the 2v headers and a 2v dual plane then those parts cannot be reused (and they are not cheap)

Here is what I would do:

Decide if I want to build a motor or not. If so, plan out and buy parts for that motor while keeping the cost down on this one. I would leave the single plane intake and go dual exhaust but not purchase headers until I determined my final build and if I am keeping 2v heads, then get the headers.

If you decide that you don't want to build a motor then I would replace the intake, get some headers, put in a decent aftermarket ignition and swap out the rear end gears for 3.50's. If that doesn't give you what you want then go with a cam but keep the lift/duration at a reasonable level.

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

Pics of modifications included in:
Sly, you really bring up an INTERESTING point which I do not believe is always taken into consideration when asking for (or giving) advice on issues like the one you seem to be trying to raise. It should be noted that "More Performance" is relative. Specifically, what is more (or better) performance in one person's mind may not be the same thing in another person's mind.

For example, are you looking for quicker acceleration or a higher speed over a specified covered distance? Is your car "running out of breath" when you want it to go "more" over a certain distance or in a specified time? The response to each of these questions could entail entirely different approaches.

Quite frankly, sometimes a simple change in rear end gear or final drive ratio can satisfy that alleged "need for more speed" which often equates to a "need for more quickness." Hence, the reason I believe Chuck inquired about the differential that you are using.

Most mass produced vehicles are built to address specific needs or desires of consumers. That is why we have Mach 1s and daily Coupes from the 1971 - 1973 Mustang period sharing the same basic engines (in many cases) why being configured somewhat differently. They each are designed for a specific market. It is pretty much about COMPROMISE.

With that having been said, it is much better to make a SINCERE assessment of how you want to utilize your Mustang MOST of the time. Once that is done, you can then address what specifically needs to be changed and/or modified.

Just a thoughtSmile.


Do the RIGHT thing.
Best bang for the buck 3.50 gears and a good dual exhaust. Then see if you need more motor at this point. My stock 351C 2V became more fun to drive when I pulled out the 3.00 open diff and installed the N case 3.50 T/loc diff. Or compromise 3.25s if you spend allot of time on the freeway.
Thanks a lot, this forum rules Smile
I think I have many options right now as I can read.

Good dual exhaust is for sure the next investment. As Will said, if I plan to go 4V I'll wait to get the Hooker Headers.

Something like this to put in my Cleveland ? 1970 4V closed chambers heads

Will this fit ? Won't this play on the compression ratio ? 4V heads from before 1972 sound like a better base and not too exepensive to get a bit more HP. I will check out the 3.50 gears too
Performance is best achieved as a "Package", so don't think of as just adding a part here & there. Other than adding a 4bbl carb/aluminum intake and dual exhaust, the best bang for the buck is lowering rear gear ratio. If you go for cams, aluminum heads and other spendy parts, a lower rear ratio will be needed any way, to take full advantage of your investments. An overdrive 5 speed or AODE/4R70W will allow you those loer ratios with out having you turn 3200 RPM @ highway speeds. As for ratio, why limit yourself to 3.50's?? Go for 3.75's and then keep your fuel milage with an overdrive transmission. That is how the modern cars are done.
Yes I know, there's not one thing to change but tons of things, then it's a non ending race to performance and $$$. And needless to say more performance = more problems with engine durability, etc.
Overdrive 5 speed manual transmission would be amazing but they are very expensive especially here in Europe. Someone in my family used to have a 71 Coupe with manual transmission and he said it was very impressive !

So in the first place, in my case, what do you think of :
- lowering rear gear ratio ?
- buying 4V heads from a 70-71 Cleveland ? Then start from here to change parts in the motor (someday : pistons, cams etc.) ? I think I can find some good used heads on ebay and get them to ship here. Do you think I'll notice a difference with 4V heads, new intake and the same carb ? (Holley 600)
What rear gears do you have now?
Changing to 3:50 gears will give you more acceleration but also it will suck more gas on the highway (much lower kilometers/liter). Gas in France is not cheep.
Keeping the 2v heads would be better than 4v heads. The valves on the 4v are too big for street use. They are good for high RPM racing but 2v heads are better for low end power. Plus you'll have to buy a new intake to fit the 4v heads and the 4v heads will suck even more gas.

My suggestion is to get dual exhaust with good performance mufflers and retune your distributor for more and quicker advance. You'll have to use premium octane gas but you'll also get better gas mileage (better kilo/liter). You'll also see much better performance for not much money.

1971 Mach1
C6 is history-->>now TKO-500
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