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Discussion Starter · #1 ·
Greetings B-Fam! Has anyone installed headers on an inline 6 4wd? I keep seeing this, Hedman Hedders 89300, but it says 2wd only. I’m assuming there is a transfer case issue. You guys have been great on direction before. :) l’m hoping for the trifecta help win :) thanks guys!
 

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Discussion Starter · #4 ·
You shouldn’t have any transfer case issues with a 300 since all the exhaust exits on the pass side. Maybe @BigBlue 94 has a good idea on headers.
Thanks for the quick flip! I’ll hang and see if I can get confirm on being able to buy those!
I believe @BigBlue 94 recommends late model 300 6 manifolds, as they are split manifolds.
Would that split help th3 performance a bit? I figure since I’m swapping out the OG, I was going to install proper headers and a custom Stainless steel 3” dual pipes out the back corners.
 

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@BigBlue 94 has all the low down "Experience" on the 300/6 you'll ever need to know! He will chime in soon enough.
 

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Hey there, i have a set of Clifford headers on my 85 bronco. They are a 1 5/8 primary with 2.5" collectors. For the utmost power out of a 300, headers are a necessity. But we are talking 300HP+ builds. The cliffords were on mine when i got it. For a solid 250hp build, the 87-96 EFI exhaust manifolds will serve you fine and keep the engine compartment cooler. They are essentially a shorty header made from cast iron.

Cons of the long tube: difficult to install, create a LOT of heat, and need a completely custom y-pipe.

Pros: they sound great and make a tiny bit more power. A similar sound can be achieved with the manifolds with a flowmaster scavenger series y-collector. Its what i use for my exhausts.

I cannot comment on the hedman headers. They may interfere with suspension. Someone on the fordsix.com forum could tell you.

The efi manifolds have a couple available y-pipes, but custom will flow better. One option is to find a good factory 87-96 y-pipe and use the headpipes to make your own y-pipe. I would definitely recommend the efi manifolds if you plan on offroading, solely for the heat problems with long tubes.

Either type will really wake up any 300. They respond well to a high flowing exhaust

My setup:






Have you done anything to your engine or is it bone stock?
 

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Discussion Starter · #7 ·
Holy smokes, that’s a lot of info and great pics. The efi manees are the cast iron split ones correct? I plan on having everything from collectors back custom built. I do plan on pff reading and want the keep it as cool as possible. Thank you so
Much for the info!
Hey there, i have a set of Clifford headers on my 85 bronco. They are a 1 5/8 primary with 2.5" collectors. For the utmost power out of a 300, headers are a necessity. But we are talking 300HP+ builds. The cliffords were on mine when i got it. For a solid 250hp build, the 87-96 EFI exhaust manifolds will serve you fine and keep the engine compartment cooler. They are essentially a shorty header made from cast iron.

Cons of the long tube: difficult to install, create a LOT of heat, and need a completely custom y-pipe.

Pros: they sound great and make a tiny bit more power. A similar sound can be achieved with the manifolds with a flowmaster scavenger series y-collector. Its what i use for my exhausts.

I cannot comment on the hedman headers. They may interfere with suspension. Someone on the fordsix.com forum could tell you.

The efi manifolds have a couple available y-pipes, but custom will flow better. One option is to find a good factory 87-96 y-pipe and use the headpipes to make your own y-pipe. I would definitely recommend the efi manifolds if you plan on offroading, solely for the heat problems with long tubes.

Either type will really wake up any 300. They respond well to a high flowing exhaust

My setup:






Have you done anything to your engine or is it bone stock?
bone as of this moment.
 

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Yes, efi manifolds are the split manifolds (1,2,3 and 4,5,6) made of cast iron. Factory parts on 87-96 F-series and E-series and bronco 87-92.

This is what they look like
http://www.supermotors.net/getfile/716731/fullsize/intake-removed.jpg

Since you plan to offroad, I would definitely choose the efi manifolds. A 2.25" y-pipe into a single 3" muffler (and cat if you want) and single tail pipe is a tried and true setup. Mine is 2.5 into 3".

The only other option is the HD log exhaust from 300s in the medium duty line like f600 and f700. But they arent as good as the efi manifolds. And rare.

After you do the exhaust, or at the same time, consider swapping to a better intake (clifford, offenhauser C, or aussie speed) and a 2 or 4 bbl carb. Combined with the exhaust, this will add about 80 HP to your measly 120hp you have currently. I ran mine like that for a while, before i had to rebuild it. It makes for a strong engine.
 

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Look at those pretty roller rockers!

I always thought the EFI 300s looks like they had an ideal manifold in terms of maximizing that off-idle torque the 300s are known for.
 

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Look at those pretty roller rockers!

I always thought the EFI 300s looks like they had an ideal manifold in terms of maximizing that off-idle torque the 300s are known for.
Lol and the $500 jethot that was pointless...

Harland Sharp 1.6 ratio rockers specifically for the 300. Ive got a Schneider 140H cam and 9.75:1 compression with 1.96 and 1.6 valves. It screams up to 5500 rpm then quickly falls on its face lol.
 
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Is that due to the cam grind or valve float?
Likely not enough air through the chitty u-port head, and the cam. Cam is fairly large, but not huge. 280° ADV duration, 222° @.050, .480 lift, 110 LSA, 2400-6000 rpm range (in a 240i6, which is about 1000 rpms higher on both stats than it runs in a 300). Though ive pretty well found it makes power at 1000-5500 on my setup.
 
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The 2WD vs 4WD headers is due to the TTB front axle. The 2WD axle gives a little bit more room to snake around.

I have a pretty aggressive engine build in mine as well, but I opted to stick with the EFI manifolds. They're a great exhaust setup, easy to install, and easy to come by. I can still easily scream up to 5500 - 6000 RPMs, and it'll pull the whole way. It's got a big cam, roller rockers, enlarged valves, and a professional port and polish job to tie it all together.






Headers aren't necessary for getting big power out of the 300, but they certainly do help. Just don't think you have to get them.
 

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Likely not enough air through the chitty u-port head, and the cam. Cam is fairly large, but not huge. 280° ADV duration, 222° @.050, .480 lift, 110 LSA, 2400-6000 rpm range (in a 240i6, which is about 1000 rpms higher on both stats than it runs in a 300). Though ive pretty well found it makes power at 1000-5500 on my setup.
Didn't the Aussies make some mean sixes with a better head? The American 300 is like a diesel engine in durability with gear driven cam and bomb proof bottom end, but the head isn't even a cross flow and the ports must be constricted. I seem to recall reading about the Australian big six having some modernized variants including aluminum DOHC variants.

Headers aren't necessary for getting big power out of the 300, but they certainly do help. Just don't think you have to get them.
Just replace the headers with a log manifold and add a small turbo. I wonder how long the little 8.8 will last before a boosted 300 pops the ring and pinion :LOL:
 

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Didn't the Aussies make some mean sixes with a better head? The American 300 is like a diesel engine in durability with gear driven cam and bomb proof bottom end, but the head isn't even a cross flow and the ports must be constricted. I seem to recall reading about the Australian big six having some modernized variants including aluminum DOHC variants.



Just replace the headers with a log manifold and add a small turbo. I wonder how long the little 8.8 will last before a boosted 300 pops the ring and pinion :LOL:
Not for the BB6 they didnt. I recently posted a pic of one of the maybe 2 or 3 300s with a DOHC head. Fully custom. However, Ford Australia did come out with the 4.1L Barra Six, which is a DOHC and is capable of over 1000 with forced induction.

But yes, the 300 is a tractor engine. In fact it is the engine with the longest streak of being used as standard in new equipment. Ford sold the rights off and the new owners are still making 300s for equipment like water pumps, generators, and other things that need power.

Aussie Speed is a company that makes speed parts, from Australia. The 300 is still huge there. Their manifold is very similar to the old holman-moody piece, with long runners.

Ford, here in the states, did produce a few pallets worth of BB6 crossflow heads back in the 60s or early 70s but scrapped them. The Frenchtown Flyer (youtube, fordsix forums) owns probably the only 2 in existence. They are capable of 600 HP NA.
 
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I would love to have one of those heads. Then again, I think I'd be scared to run it out of fear of hurting it and it'd sit on a shelf collecting dust.

Aussie Speed is coming out with some good stuff. Just installed one of their intakes on my cousin's 300 along with a Holley Sniper. There were a couple fitment issues (like one of the studs had no space around it for a nut, so we had to grind a groove), but overall it's well made. The truck also ran amazing once done.

They've also posted that they're creating their own cast iron "EFI" manifolds here soon in the future, with improved flow. I'm looking forward to those, and will probably be first in line for a set.
 
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Hey there, i have a set of Clifford headers on my 85 bronco. They are a 1 5/8 primary with 2.5" collectors. For the utmost power out of a 300, headers are a necessity. But we are talking 300HP+ builds. The cliffords were on mine when i got it. For a solid 250hp build, the 87-96 EFI exhaust manifolds will serve you fine and keep the engine compartment cooler. They are essentially a shorty header made from cast iron.

Cons of the long tube: difficult to install, create a LOT of heat, and need a completely custom y-pipe.

Pros: they sound great and make a tiny bit more power. A similar sound can be achieved with the manifolds with a flowmaster scavenger series y-collector. Its what i use for my exhausts.

I cannot comment on the hedman headers. They may interfere with suspension. Someone on the fordsix.com forum could tell you.

The efi manifolds have a couple available y-pipes, but custom will flow better. One option is to find a good factory 87-96 y-pipe and use the headpipes to make your own y-pipe. I would definitely recommend the efi manifolds if you plan on offroading, solely for the heat problems with long tubes.

Either type will really wake up any 300. They respond well to a high flowing exhaust

My setup:






Have you done anything to your engine or is it bone stock?
Yo @BigBlue 94 so why don't you switch back to the EFI cast exhaust manifolds to beat your heat problem? You could port match and Extrude Hone if you want them to be all they can be!!!!!
 

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Yo @BigBlue 94 so why don't you switch back to the EFI cast exhaust manifolds to beat your heat problem? You could port match and Extrude Hone if you want them to be all they can be!!!!!
Because i have a lot of money invested in them and my exhaust is custom built for them. I do have a set of efi manifolds om the shelf though. Some day ill probably swap over.
 

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Because i have a lot of money invested in them and my exhaust is custom built for them. I do have a set of efi manifolds om the shelf though. Some day ill probably swap over.
I know what you have and what you built but since you're a wiz with the "Ideas" and "Welding" I would think outta curiosity you could whip up some adapter tubing to make it work with your existing fancy Y-pipe you created!!!! To be able to give a first hand comparison of the 2 exhausts!!! Just sayin ya know!
 
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