Headers

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Aug 27, 2021
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Williamsburg Virginia area
My Car
1972 H code convert., 351C 2V, FMX, 9in., Ram air, Pwr Steering, Pwr Disc brakes, air-conditioning, 15" sport wheels, Ivy Glo w/white deluxe interior.
Good evening all. Hate to be all over the boards like a starburst but it always seems that being forced to do repairs outside the attempt at a schedule for them is making for some out of sequence purchases. Here it would be headers.

I've been looking at the Shorties sold by Stangaholics over the long tube version of our youth. To be very honest, Out of the 4 classics I've owned, a '66 notchback, '71 Cougar XR7, '66 F100 and now the '72 convertible, only one has had headers, so far. The '66 had a 351W shoehorned into that engine bay so heavy mods (courtesy of the BFH method) only allowed for stock manifolds. The Cougar was at the tail end of my College life and cars were starting to be replaced by career. The F100 was actually my best shot as an adult at making some of my youthful dreams of huge power and weekend fun a reality but as an adult, it came down to taking care of our daughter becoming heavily committed to year-round swimming and attending (swimming too) in college herself.

Now, we're past the clubhouse turn by a few holes and this is it. Okay, long story over, I get that both styles of headers provide different engine performance but we're talking about "realizaxing" (realizing that I need to be more relaxed when it comes to horsepower). That said, I've been leaning toward the shorties heavily.

Since I need to install the new quick-ratio Lares PWS box, figured we'd just add headers so, has anyone used the shorties? They look like they will mount in almost the stock manifold location with the exhaust. The reason I ask is, the exhaust in the car is fairly new and it would be nice if it could be used without major modifications. It is dual so what are the thoughts?

Given the 90 day return on the old steering head for refund of the $200 core charge is playing a role and needing the car to be down for less than a day or two is the other. BTW, the nice thing about the shorties is, I can order the ones for 4v heads and get the adapters until I actually pull the motor to install them. Didn't want to see what happens when I install a nice clean new set of cc 4V heads on a what by that time will probably be 53-54 year old motor. I can't even think of a description of what could happen in that scenario other than a possible oil pan failure.
 
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There have been quite a few dyno tests done on the power differences that are realistic using manifolds / shorties / equal lenght 4-tube full length headers on 289/302/351 based engines. Kinda suprisingly, the shorties offer hardly any more power than Hi-Po manifold with dual exhausts. The dyno pulls indicate that the full length headers are best power improvement over anything else. That having been said, I haven't read any dyno testing on our Cleveland based engines using manifiolds / shorties/ or four tube headers, so referencing the above may be of little value. I tend to think that the shorties may look to be an improvement, but for the trouble, I think I'd just bite the bullet and put on full length headers. Yes, they are more work to install, but you will likely be visiting the Muffler Shop anyway, so they can hook you up with either the complete install, or just attaching the new exhaust to your existing pipes. I have been running manifolds and duals since I bought the car some 33 years ago with no complaints, but yes, many times I have thought about Headers. My thing is I like my car to Purr, rather than Growl.
 
Headers are just part of the equation. If your engine is stock and you want to increase low end power the shorties may help a bit. Take a look at some online videos that talk about options between long tube and short tube. It’s all about the pulsation feedback from your collector to help you tune in power at your preferred rpm range. Shorties typically help at lower rpm and long tubes at higher rpm. Looking at your goals I would guess you are hunting in the right park anyway. Let us know if you feel a change in power through the rpm range.
 
Headers are just part of the equation. If your engine is stock and you want to increase low end power the shorties may help a bit. Take a look at some online videos that talk about options between long tube and short tube. It’s all about the pulsation feedback from your collector to help you tune in power at your preferred rpm range. Shorties typically help at lower rpm and long tubes at higher rpm. Looking at your goals I would guess you are hunting in the right park anyway. Let us know if you feel a change in power through the rpm range.
Jack Roush had a couple of articles in Hot Rod Mag about building a solid 351C 4V engine for street use. He discussed the effects of primary tube size and length. I'd have to really dig for that old article, but I used it as my guide when I built the engine for my '72 Mach 1. It was basically all factory sourced parts except for the Hooker 1 3/4" primary tube long headers dumping into 2 1/4" duals through turbo mufflers.
 
It is all about what you want. If you are looking for every last ounce of power then long tube headers are needed. If that is not the case there is nothing wrong with shorties or stock exhaust manifolds for that matter.
 
It is all about what you want. If you are looking for every last ounce of power then long tube headers are needed. If that is not the case there is nothing wrong with shorties or stock exhaust manifolds for that matter.
I agree to a point. My '72 Q code convertible has the factory exhaust manifolds on it, but during my head refresh in 2017 I used my die grinder and carbide burrs/sandpaper rolls to clean up the internal flash and bumps. There was a big restriction right where the pipes hook to the manifold outlets. I opened those up to match the 2 1/4" pipe I.D.s. the engine really liked it. I wasn't going to change the manifolds out on that car, I only make "hidden" mods on that one, like putting in a '71 Q code cam to get the 4° advance back in it.
 
Headers are just part of the equation. If your engine is stock and you want to increase low end power the shorties may help a bit. Take a look at some online videos that talk about options between long tube and short tube. It’s all about the pulsation feedback from your collector to help you tune in power at your preferred rpm range. Shorties typically help at lower rpm and long tubes at higher rpm. Looking at your goals I would guess you are hunting in the right park anyway. Let us know if you feel a change in power through the rpm range.
Sorry but you have it backwards. Long primary tubes are better for low rpm/torque. Higher RPM engines prefer shorter primaries. A lot of videos are made by keyboard physicists who haven't got a clue. Check out NHRA Stockers that generally don't go much over 7000 RPM. They use long primaries and collectors. Then look at Competition Eliminator engines that turn 9000-10,000 RPM. They use short headers and collectors.
 
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Sorry but you have it backwards. Long primary tubes are better for low rpm/torque. Higher RPM engines prefer shorter primaries. A lot of videos are made by keyboard physicists who haven't got a clue. Check out NHRA Stockers that generally don't go much over 7000 RPM. They use long primaries and collectors. Then look at Competition Eliminator engines that turn 9000-10,000 RPM. They use short headers and collectors.
You need to compare apples to apples. Eliminator is just blowing exhaust to atmosphere, there is no back pressure to send a resonance wave back to the exhaust valve. In normal closed systems the long tube headers allow for a longer distance before sending a pulse back to the exhaust valve which helps scavenge the cylinder at a higher rpm if that's what your engine is built for, thus more power at higher rpm with a long tube. Short tube has a shorter travel distance before there is a restriction causing the resonance pulse to head back to the exhaust valve sooner which helps scavenge the cylinder at a lower rpm as long as your timing events are geared towards power in the midrange. Basically the length of the tubes should be a predetermined component in your build. Switching long vs short is the same as any other component, you only get better when you are planned for.

Here, give this a read. https://blog.tdotperformance.ca/gui...u5lw3n0yHys2K6YMgc4nmIuWlvP4fauhoCn6MQAvD_BwE
 
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You need to compare apples to apples. Eliminator is just blowing exhaust to atmosphere, there is no back pressure to send a resonance wave back to the exhaust valve. In normal closed systems the long tube headers allow for a longer distance before sending a pulse back to the exhaust valve which helps scavenge the cylinder at a higher rpm if that's what your engine is built for, thus more power at higher rpm with a long tube. Short tube has a shorter travel distance before there is a restriction causing the resonance pulse to head back to the exhaust valve sooner which helps scavenge the cylinder at a lower rpm as long as your timing events are geared towards power in the midrange. Basically the length of the tubes should be a predetermined component in your build. Switching long vs short is the same as any other component, you only get better when you are planned for.

Here, give this a read. https://blog.tdotperformance.ca/guides/short-tube-vs-long-tube-headers-w
You need to compare apples to apples. Eliminator is just blowing exhaust to atmosphere, there is no back pressure to send a resonance wave back to the exhaust valve. In normal closed systems the long tube headers allow for a longer distance before sending a pulse back to the exhaust valve which helps scavenge the cylinder at a higher rpm if that's what your engine is built for, thus more power at higher rpm with a long tube. Short tube has a shorter travel distance before there is a restriction causing the resonance pulse to head back to the exhaust valve sooner which helps scavenge the cylinder at a lower rpm as long as your timing events are geared towards power in the midrange. Basically the length of the tubes should be a predetermined component in your build. Switching long vs short is the same as any other component, you only get better when you are planned for.

Here, give this a read. https://blog.tdotperformance.ca/gui...u5lw3n0yHys2K6YMgc4nmIuWlvP4fauhoCn6MQAvD_BwE

hich-is-best-for-your-exhaust/?utm_source=google&utm_medium=cpc&utm_campaign=ToF_Search_PerformanceMax_&utm_term=_&gad_source=1&gclid=CjwKCAjw5ImwBhBtEiwAFHDZx2NF4C6AeM-Cq6-7QmhBTgu5lw3n0yHys2K6YMgc4nmIuWlvP4fauhoCn6MQAvD_BwE
 
Jack Roush had a couple of articles in Hot Rod Mag about building a solid 351C 4V engine for street use. He discussed the effects of primary tube size and length. I'd have to really dig for that old article, but I used it as my guide when I built the engine for my '72 Mach 1. It was basically all factory sourced parts except for the Hooker 1 3/4" primary tube long headers dumping into 2 1/4" duals through turbo mufflers.
Funny, the project is not further along by much, if any at all from the post of this topic last year. One thing for certain, well two things for certain, the car is more disassembled than I like for comfort and if we're talking about people who have it down with Ford engines, Robert Yates name definitely belongs being said with Jack Roush's. Although, I'm not sure about what he may have documented about the 351C during his life. It might be a worthwhile look further into things.
I suppose that I should re-explain the intended reason behind the "shorties" use. I can't find a single pair of 4V head exhaust manifolds for the 1971-72 mustangs. I did find a pair that were engine specific, but the exit angle is different if it was anything other than a Mustang. From what I gathered; it was more a downward exit versus a more rearward exit. Or was that versa visa?
Didn't want to try and "manipulate" a set of long tubes into place and really just wanted to realize more of a sound benefit than power. Especially knowing full well by the time things were finished, making extra bottom end wasn't going to be something I was concerned with so making the kind've horses/torque that happen at high RPM's is not in the realm of my reality either. Things have changed with regards to how street antics are viewed but it's not for the better and I've been living in a "no points zone" on my DL for a very long time.
 
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Funny, the project is not further along by much, if any at all from the post of this topic last year. One thing for certain, well two things for certain, the car is more disassembled than I like for comfort and if we're talking about people who have it down with Ford engines, Robert Yates name definitely belongs being said with Jack Roush's. Although, I'm not sure about what he may have documented about the 351C during his life. It might be a worthwhile look further into things.
I suppose that I should re-explain the intended reason behind the "shorties" use. I can't find a single pair of 4V head exhaust manifolds for the 1971-72 mustangs. I did find a pair that were engine specific, but the exit angle is different if it was anything other than a Mustang. From what I gathered; it was more a downward exit versus a more rearward exit. Or was that versa visa?
Didn't want to try and "manipulate" a set of long tubes into place and really just wanted to realize more of a sound benefit than power. Especially knowing full well by the time things were finished, making extra bottom end wasn't going to be something I was concerned with so making the kind've horses/torque that happen at high RPM's is not in the realm of my reality either. Things have changed with regards to how street antics are viewed but it's not for the better and I've been living in a "no points zone" on my DL for a very long time.
https://www.facebook.com/marketplace/item/878240437375819
 
Didn't want to try and "manipulate" a set of long tubes into place and really just wanted to realize more of a sound benefit than power. Especially knowing full well by the time things were finished, making extra bottom end wasn't going to be something I was concerned with so making the kind've horses/torque that happen at high RPM's is not in the realm of my reality either. Things have changed with regards to how street antics are viewed but it's not for the better and I've been living in a "no points zone" on my DL for a very long time.

The Hooker Comp 6915HKR are for 4V heads and slip right into place without any modifications or denting of tubes. 6921 is the 2V version.

The passenger side 4V manifold was the same 70-74.

The driver's side changed for the 71 Mustang due to the placement of the clutch Z-bar.

70 Mustang / Cougar 70-71 Torino/Montego - D0AE-9430-G
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71-73 Mustang/Cougar 72-74 Torino/Montego - D1ZE-9430-BA

1711587611593.png
 
By the way, thanks for the pics Hemikiller. That shows what I was trying to explain. I have found several of the earlier driver's side but the one or two that I did run across were sold or boo coo bucks and not worth it since I'm not looking for a concourse car.

Well, if that's the case, I can save a few bucks by going with the long tubes. I'm going with the 4V headers to start since the plan to use the heads I have remains in place. I believe there is an adapter, and this might be the answer for the next question so... a quick question revolving around the heads and bolt pattern, I remember something somewhere said at some point in time over the last 50 years that they differ between 2v and 4v? Like I just said, maybe know the answer but confirmation, one way or another is invaluable at avoiding any return shipping charges. Those can be a killer these days.

The heads I have, the numbers identify them from late '69, closed chamber and the smaller version chamber too boot. We know they aren't Boss heads given the missing machining for guide plates but as I mentioned earlier, in a different post (I believe I did) the rocker studs are of the screw-in type. All that said, a very close friend who knows volumes more than I do about the differences out there mentioned they may be from a '69 Cobra Jet in originally. Just don't know if it was a Mustang, Torino, Cyclone, Ranchero (not the Huevos variety) or Country Squire. Yes, fully understand it's really a rebadged 4V but that was later when it was phased out and it's HP was less than a standard 4V. In 1969, it really meant something.

All in all, it doesn't really mean much given I don't have the 4-bolt main block and forged crank to pair with it but having a bit of history in my possession, while it's not going to increase the value once installed, it's more the feeling and being reminded of what things were like when I was far younger.
 
Chuck,
Thanks! I was able to pull up the pic and saw the price tag but that's all I could get before the door slammed shut since I don't and won't ever again do Facebook. Really! Not to get off topic by too much, it was a horrific experience when it first started and haven't been back since. Even went as far as following the steps to erase my existence from it way back when.

I've kind of moved past the stock 4V manifolds because of the cost/availability thing but if it was a set for the two bills, I could probably justify it to the DW. She's taken a monetary interest in things after seeing the stack of receipts I've built since January. Now all I need to do is find a way to 'splain the new scroll air compressor I'm buying. It's the whole ask/beg conundrum and one that has served me well for the last 30 years. The squirm dance is always a little bit of fun, once you learn to not put your feet in your mouth.
 
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