Shorty Headers vs. stock exhaust manifolds on '73 440

[Charger Fan]

Building my 440 for street and highway cruising. Pushing 400 HP, nothing to radical. Any real advantage to using shorty headers headers vs. the current stock manifolds?

 

[furious70]

Basically every Dyno test ever has shown headers help both tq and hp

 

[GTX JOHN]

If you have the HP 73 manifolds, the headers are not
much of a difference through the exhaust in my testing.
The maintenance can be a pain on a street car that is daily driven
with the headers.

 

[WileERobby]

If you have the HP 73 manifolds, the headers are not
much of a difference through the exhaust in my testing.
The maintenance can be a pain on a street car that is daily driven
with the headers.

What maintenance would that be ?

 

[Kern Dog]

If you have the HP 73 manifolds, the headers are not
much of a difference through the exhaust in my testing.
The maintenance can be a pain on a street car that is daily driven
with the headers.

I run into dudes like this at almost every car show. "In my testing" probably consists entirely of the foot and butt dyno, not actual data.
Exhaust manifolds never have a power advantage over headers, they don't even come close.
Even a 318 with a stock .373 lift cam will see benefits from headers.
The guys that buy cheap headers are the ones that make claims like this one. Yeah, burned spark plug wires, blown out gaskets and poor ground clearance is what you'll get when you buy the Harbor Freight quality headers.
I have 17 years on a set of 2" TTIs in my Charger. The gaskets don't blow out. The headers don't rattle. The headers are expensive but they allow the engine to breathe and run hard.
Mopar Muscle magazine did a dyno test 10 or more years ago on a basic 300 HP 360 Mopar Performance crate engine. The 340 manifolds made 7 HP more than 318 manifolds. The long tube, equal length headers added something like 22 HP and the shorty headers they had was somewhere in between. This is with what was basically a stock replacement 5.9 Magnum for trucks and vans, not the hotter 380 HP version.
Imagine a 440 with a bit more cam and carburetor...You're looking at 30 HP on a stock 440 and far more on an engine with more cam and compression.

 

[Darter6]

If shorty's are your goal, I like the Schumacher Tri-Y's. Had them on 2 different big block street cars.
I have used TTI's small block shorty's that are excellent but not the big block.

 

[WileERobby]

I run into dudes like this at almost every car show. "In my testing" probably consists entirely of the foot and butt dyno, not actual data.
Exhaust manifolds never have a power advantage over headers, they don't even come close.
Even a 318 with a stock .373 lift cam will see benefits from headers.
The guys that buy cheap headers are the ones that make claims like this one. Yeah, burned spark plug wires, blown out gaskets and poor ground clearance is what you'll get when you buy the Harbor Freight quality headers.
I have 17 years on a set of 2" TTIs in my Charger. The gaskets don't blow out. The headers don't rattle. The headers are expensive but they allow the engine to breathe and run hard.
Mopar Muscle magazine did a dyno test 10 or more years ago on a basic 300 HP 360 Mopar Performance crate engine. The 340 manifolds made 7 HP more than 318 manifolds. The long tube, equal length headers added something like 22 HP and the shorty headers they had was somewhere in between. This is with what was basically a stock replacement 5.9 Magnum for trucks and vans, not the hotter 380 HP version.
Imagine a 440 with a bit more cam and carburetor...You're looking at 30 HP on a stock 440 and far more on an engine with more cam and compression.

Yep. Over and over it's repeating the same old wive's tales, like a few other things. Example: changing plugs with headers. How often does one change plugs ? Every week ? Especially nowadays if the car isn't regularly used. I can change plugs in a half-hour. Most times the complaints originate from guys who have no business working on cars, all they have is a spark-plug socket and a rachet, and expect the plugs to pop out without barely leaning over the car. As far as a performance gain, there's no debate.

 

[Bee1971]

Are the 72-74 Exhaust Manifolds more restrictive then the 68-71 HP Manifolds or the same

 

[OldGuyGTX]

I run into dudes like this at almost every car show. "In my testing" probably consists entirely of the foot and butt dyno, not actual data.
Exhaust manifolds never have a power advantage over headers, they don't even come close.
Even a 318 with a stock .373 lift cam will see benefits from headers.
The guys that buy cheap headers are the ones that make claims like this one. Yeah, burned spark plug wires, blown out gaskets and poor ground clearance is what you'll get when you buy the Harbor Freight quality headers.
I have 17 years on a set of 2" TTIs in my Charger. The gaskets don't blow out. The headers don't rattle. The headers are expensive but they allow the engine to breathe and run hard.
Mopar Muscle magazine did a dyno test 10 or more years ago on a basic 300 HP 360 Mopar Performance crate engine. The 340 manifolds made 7 HP more than 318 manifolds. The long tube, equal length headers added something like 22 HP and the shorty headers they had was somewhere in between. This is with what was basically a stock replacement 5.9 Magnum for trucks and vans, not the hotter 380 HP version.
Imagine a 440 with a bit more cam and carburetor...You're looking at 30 HP on a stock 440 and far more on an engine with more cam and compression.

....and heads designed for the 440.

 

[Shenango]

True story. When my 66 Belvedere came to me it had a very healthy 440 with headers plus a new set of Doug's d452 ceramic coated headers. It also came with a bad mini starter. To change the starter I had to drop the driver's side header. That is not as simple as it sounds. First, spark plugs come out, then wire loom had to come off, then anti freeze has to be drained, then the collector has to disconnect from the exhaust. So there is 45 minutes of prep work just to get a hand on the starter. Since then I have replaced the kick down cable, the power steering gear and the shift cable for my ratchet shifter all at different times. Every repair on that side needed the header out of the way and that entire prep procedure had to be done.
If you have a cruiser or weekend driver that will never see track time the extra 30 HP and 20fp torque will not be worth it at all, period. When my headers burn out or rust through, and they will, I have a nice set of hp manifolds to go on. The Doug's? I sold those a long time ago, I don't need the hassle any more.
Jerry

 

[lewtot184]

This is another one of those arguments that will never cease. As for me I look at camshaft valve timing concerning this matter. Some profiles can be seriously stiffled with cast manifolds and some can work with cast manifolds. But, even those builds that can work with cast manifolds would benefit from a better exit off the port, more volume in the exhaust, and more runner seperation. I run both in my cars, but I wouldn't do some things with the cast manifold engine I'd do with the header engine. I think the cheap header thing is very valid. We know we usually get what we pay for.

 

[rumblefish360]

In all the testing I have seen, headers always win.
Now the big thing here is a possible slight confusion between shorty headers and full length headers.

The shorty header I never recommend for anything or anybody because the full length header delivers more power everywhere. While the shorty improves power, it’s not as much as a full length header by far. If you can find a dyno power graph of exhaust manifolds vs full length headers, out the shorty in between the lines with a slight less than the half way mark between the lines.

If you decide on a full length header, don’t be cheap and use one that doesn’t affect ground clearances up front. Cheap small block headers are like this. Personally I have used TTI headers with excellent results everywhere.

The draw back to headers besides road clearance on some units is changing starters and spark plugs. While this isn’t done often, when the time comes, it can be a bitching fest.

Some people will change spark plugs often because there ether not well tuned to start with and/or there at the track a lot. Once the right tune of the carb and distributor are found, changing plugs should be once a year at most if driven a lot like a daily driver. I’d call that to much if it was more than once a year. It once you get your tune in, you should be good for a while.

The exhaust manifolds may give up power. Sure! But they’re not bad on all other fronts. Those big old iron manifolds last forever, there quite where it counts, rock solid repeatable performance and use in any condition. Bolt them on and it’s a one and done.

Getting good street results for power and speed can be enhanced elsewhere on the entire car. The exhaust manifolds can certainly use different cam timing specs to be at their best. Talking this over with a cam company can help big time. I’d try a smaller but well in the good reputation category to talk with like Howard’s, Bullet and Schneider racing cams. Tell them everything about the car, drive train and your goals. This way the cam gets done for the exhaust method being used. Exhaust manifolds, shorty or full length headers in the tube size your using.

 

[RemCharger]

I run into dudes like this at almost every car show. "In my testing" probably consists entirely of the foot and butt dyno, not actual data.

You won't run into this dude at a car show. He races stock/ superstock.

 

[70bigblockdodge]

I've got free headers on my Charger, how is that for cheap headers and god know waaaaaay less money than those overpriced boat anchors.
I've had to change my starter with headers. Never had to drain the antifreeze. I must have done something wrong? Can anyone guide me on what I did wrong? I would much rather have a excruciating painful time like everyone else with headers.
I know that waiting 2 hours for the exhaust manifolds to cool down is perfect.
Headers for the win in all situations. Manifolds are for museum cars

 

[lewtot184]

Draining the antifreeze is for someone who won't use studs. Header bolts in wet holes is insanity .

 

[GTX JOHN]

Everything that I state on this forum and others is what I HAVE ACTUALLY
TESTED AT THE TRACK! It is actually my honest opinion = I own a dozen performance Mopars
and test something most every time I go racing. This is nearly every time the LVMS track is open since
it opened in 2000.

I stand by what I said about the shorty heads compared to HP Manifolds on a
mild street car making not much more than 1 to 1 1/2 tenths difference through
a good working exhaust system and in my personal opinion not worth the trouble.
Obviously the TTI headers would make more difference and are a better product
but that is not what the man asked about! For a Highway Cruiser and purely street difference
I do not believe you would ever notice that small a performance difference!

Where I invest my money in my Street cars is a top quality unrestrictive
at least 2 1/2 Inch Exhaust system for the best bang for the buck and the
best factory HP exhaust manifolds.

My Butt is too big to use as a Dyno.

Goggle John Irving Drag Racer
or
Jon Irving Drag Racer

To see my background for last 60 years. I spend my time at the Drag Strip
and leave the Car Shows to the waxers.

 

[Charger Fan]

Are the 72-74 Exhaust Manifolds more restrictive then the 68-71 HP Manifolds or the same

Does anyone know the answer to Bee1971 question above?

 

[Kern Dog]

Goggle John Irving Drag Racer
or
Jon Irving Drag Racer

What does eye protection have to do with exhaust flow or drag racing?

 

[70bigblockdodge]

Does anyone know the answer to Bee1971 question above?

Well, I did not test this, but they all dump into a chamber at different angles and then move into the exhaust pipe. Yes the early ones are swoopy and look better than the 60s 383-2bbl log manifolds, or the more bulbous 73-74 HP manifolds. The headers point everything in the same direction heading into the exhaust pipe, and the hot high pressure pulse dropping into the collector causes a pressure drop which scavenges the next pulse.
Do this experiment.
Place a napkin on any port on a exhaust manifold. Blow a very quick blast of compressed air into any other port. It will blow the napkin off of whatever port you put it on. Do the same test with a header it will not blow the napkin off, if it does you probably need a better set of headers.

 

[rumblefish360]

What does eye protection have to do with exhaust flow or drag racing?

That may depend on where the exhaust exits and it’s direction coupled with the size of the hole in the floor…..


LMAO