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300 HD heavy duty exhaust manifold

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econovan
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300 HD heavy duty exhaust manifold

Post #1 by econovan » Sun Apr 19, 2009 12:26 am

Hi guys,
I couldn't find much info on these here, only that they flow better than the stock.
The efi don't fit in the doghouse of my 66 van, the clifford shorties are too expensive new and of course nothing on ebay when I'm ready to buy.
Don't know much about long tube headers but the last thing I need is more heat building up in the DH.
So the HD might just be the ticket to open her up a little?

Can anyone comment about price/performance/availability?

Thanks :)

'75 Engine has hypereutectic pistons .30 over, milled head .030, melling torque cam, MSD. stock intake/carb so far.

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Post #2 by crash-harris » Sun Apr 19, 2009 1:02 am

Pretty sure broncograveyard.com (JBG) used to have the HD mani's, but Hedman long tubes are about less than $200 from Summit.

http://store.summitracing.com/partdetai ... toview=sku
Bruiser - 1990 Ford F150...barely...EFI 300 Big Six, 500K+!, converted to 4x4. 4.10 gears and Sterling FF rear w/ Trac-Lok, 37" meats. Undergoing 1 Ton leaf spring SAS. 6BT in the plans.

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Post #3 by willowbilly3 » Sun Apr 19, 2009 3:58 am

I just saw the HD new on ebay for 2 bills.
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Post #4 by nitrousnick » Sun Apr 19, 2009 9:24 am


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Post #5 by AbandonedBronco » Sun Apr 19, 2009 10:22 am

The HD manifold flows very well. It was designed to run on large trucks that kept the 300 a 3000 - 4000 RPMs all day long.

The stock log exhaust is a single 2" outlet.
That's 3.14 square inches of exit room.

The EFI manifolds are dual 1.75" outlets.
That's 4.81 square inches.

The HD manifold is a single 2.5" outlet.
That's 4.90 square inches.

They really flow. I see them on ebay ALL the time, but usually around $200. Here's one:
http://cgi.ebay.com/ebaymotors/300-FORD-4-9-4-9L-NEW-21-2-EXHAUST-MANIFOLD_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247QQcategoryZ140696QQihZ015QQitemZ250281680844QQrdZ1QQsspagenameZWD1V

They can be spotted easily because the outlet goes straight down, instead of curving towards the rear.
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Post #6 by willowbilly3 » Sun Apr 19, 2009 2:21 pm

I wonder how they fit with exhaust manifolds. It looks like the heat exchanger is back further.
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Post #7 by AbandonedBronco » Sun Apr 19, 2009 2:43 pm

willowbilly3 wrote:I wonder how they fit with exhaust manifolds. It looks like the heat exchanger is back further.


I'm guessing since that is the exhaust manifold that you meant intake manifold? If so, it should fit together, since there wasn't a special intake for it. The only difference being I don't believe they have a heat riser.
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Post #8 by Lazy JW » Sun Apr 19, 2009 3:17 pm

The HD exhaust will NOT work with the standard, light-duty intake. The standard intake bolts to the exhaust with a three-bolt pattern, the HD uses a four-bolt pattern.

I purchased a new HD exhaust manifold a couple of years ago and have yet to install it.
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #9 by AbandonedBronco » Sun Apr 19, 2009 3:47 pm

There was a different intake? I wonder where someone would find one. I've only heard of the HD exhaust manifold, but not an intake to go with it. :shock:
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Post #10 by econovan » Sun Apr 19, 2009 6:35 pm

It looks like a three bolt pattern.

JW, could you go see since you have one?

Found the thread from 2006

http://fordsix.com/forum/viewtopic.php?t=39399&highlight=hd+exhaust

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Post #11 by Lazy JW » Sun Apr 19, 2009 7:29 pm

My HD exhaust manifold has the four-bolt pattern which will NOT bolt up to the "normal" stock light-duty intake. It also has a three-bolt pattern on the OUTLET rather than the light-duty two-bolt type.

I have never seen a HD intake with my own eyes; if anyone has one I'm interested in purchasing one.

An aftermarket intake that doesn't bolt to the exhaust can also be used.
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #12 by econovan » Tue Apr 21, 2009 11:03 pm

Thanks ABbronco :)

It's scheduled for delivery tomorrow.

What muffler should I go with?
Single or dual out?
Currently I have it out in front of the right rear wheel.


Cheers:)

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Post #13 by 66 E100 Pickup » Thu Apr 23, 2009 1:00 pm

I'm with Joe on this, been looking at these HD exhausts for a couple years and have NEVER seen the intake. I've looked at hundreds of these in the junkyards and never seen one...

It's a mystery to me why the exhaust is around, but no intakes.

John/Fresno

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Post #14 by AbandonedBronco » Thu Apr 23, 2009 1:03 pm

Is it possible they used the same intake and maybe there was just an adapter?
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Post #15 by 66 E100 Pickup » Thu Apr 23, 2009 1:06 pm

No, the 4 bolt pattern HD exhaust will NOT work on 3 bolt intake.

I even had a phone conversation with the Stevens company guy...very knowledgeable. He was the one that mentioned the problem (lost a sale too). He said he had no idea where to get an intake.

John

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Post #16 by mutt » Thu Apr 23, 2009 2:01 pm

could the intakes be better designed to flow, too? And snagged by 6ers? Or made of Al, therefore having more scrap value, hence disappearance?
Do these HD dumptruck motors run a larger bore carb? The stockers after 73 or so are like soda straws.....

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Post #17 by 66 E100 Pickup » Thu Apr 23, 2009 5:03 pm

we would have heard of that mystical intake if it had something going for it...

I would have thought the collective knowledge of everyone here would have exposed it in the last many years. Especially if it was a known performance upgrade.

John

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Post #18 by Luckyman » Thu Apr 23, 2009 5:16 pm

I've been trying to locate something about the HD intake on google every which way I can think of and not coming up with anything. :hmmm:
1 "76" F150 RC, LB, 2WD, 300, NP435, 9" open 3.00, special order 2-76/Delivered 4-76. Still "new".

1 "73-79" F150 RC/SS/SB/4WD, "84"-300, T18, NP205, 9" open 3.50, Dana 44 3.50 open, Offy DP, Holley 470, EFI + single 2.5" exhaust. Gathered from 15+ donor/parts trucks. "Fubar". Runs good, safe, still needs details/project continues.

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Post #19 by mutt » Thu Apr 23, 2009 6:22 pm

Hmmmmmm.....a conspiracy to keep "Super Six" laminar flow intakes out of circulation by those shifty bent 8 boys? Fear that we'd gain the upper hand, and expose them once & for all??They are as bent as thier quasimotors..... or does the factory have a infil/exfil commando to get them from junkyards before they fall into civilian hands? Could that be it?
bolt on 75 horse 1 bbl manifolds made of titanium disguised as cast iron....
with built in miniturbos, one in every inlet tract. Thats GOT to be it!....... Its them Bent 8ers! How ELSE do you explain the eerie paucity of manifolds!!
Lets torture some v8 owners til they tell us where they hid them! They MUST be found!

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Post #20 by econovan » Thu Apr 23, 2009 9:44 pm

edited for system error
Last edited by econovan on Thu Apr 23, 2009 11:08 pm, edited 1 time in total.

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Post #21 by Asa » Thu Apr 23, 2009 10:04 pm

econovan wrote:Sorry about that...the system just returns errors when posting.


sorry about what?
uh-oh! the ninja-moderator struck again!

dadgummed ninja....





in the future, when you get an error, don't go back and try to repost it, just find where the post should have been, and see if the post went through, if it didn't, then try to repost
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Post #22 by mutt » Thu Apr 23, 2009 10:21 pm

wheres the intake heater?

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Post #23 by econovan » Thu Apr 23, 2009 11:10 pm

I received the exhaust manifold today and took some pics.
I wish i had saved my old stock manifold that came with the 300 to compare it.

[img][img]http://i61.servimg.com/u/f61/13/21/46/94/hd_110.jpg[/img]

[img][img]http://i61.servimg.com/u/f61/13/21/46/94/hd_211.jpg[/img]

[/img]Image

[img][img]http://i61.servimg.com/u/f61/13/21/46/94/hd_410.jpg[/img]

[/img]

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Post #24 by econovan » Thu Apr 23, 2009 11:27 pm

Image

Image

Image

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Post #25 by econovan » Thu Apr 23, 2009 11:28 pm

Image

Image

Image

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Post #26 by 66 E100 Pickup » Thu Apr 23, 2009 11:59 pm

well I'm a sonamaguchi.

That joint with the intake is definitely different from the others I've seen.

Where did you get it?

John/Fresno

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Post #27 by Lazy JW » Fri Apr 24, 2009 9:01 am

That one is different than mine. The three-bolt pattern may well work with the standard intake :?:
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #28 by AbandonedBronco » Fri Apr 24, 2009 9:49 am

Thanks for the pics! That's just cool to see.

That thing definitely looks like it was made to flow.
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Post #29 by Luckyman » Fri Apr 24, 2009 10:15 am

Yep that one will work with the stock LD intake.
1 "76" F150 RC, LB, 2WD, 300, NP435, 9" open 3.00, special order 2-76/Delivered 4-76. Still "new".

1 "73-79" F150 RC/SS/SB/4WD, "84"-300, T18, NP205, 9" open 3.50, Dana 44 3.50 open, Offy DP, Holley 470, EFI + single 2.5" exhaust. Gathered from 15+ donor/parts trucks. "Fubar". Runs good, safe, still needs details/project continues.

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Post #30 by 66 E100 Pickup » Fri Apr 24, 2009 12:16 pm

where did you get it? what price?

Thanks

John/Fresno

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Post #31 by econovan » Fri Apr 24, 2009 6:56 pm


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Post #32 by mutt » Fri Apr 24, 2009 7:56 pm

looks like you can clamp that to your offy manifold.......
handsome lump indeed......

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Post #33 by econovan » Fri Apr 24, 2009 9:04 pm

I don't have an offenhauser or cliffort intake yet.
I'm looking at those and the carb options (Holley, Barry Grant or Summit)

I've tried to contact the guy "factoryblue" who posted the thread
originally but I guess he's not on here anymore.
I'd like to find out what to do about the heat opening.
In his thread he stated that there's a 1/8 space but he never mentioned if it was sufficient for carb/intake heat or to just block it off.

I was also wondering what kind of muffler I should use.

Any suggestions are welcome.

Cheers :)

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Re: 300 HD heavy duty exhaust manifold

Post #34 by krobert56 » Tue May 12, 2009 1:32 pm

saw one on a 1985 e150 on its way into the crusher couple of days ago would have been $15 if i had known what i was looking at - appeared to be a complete factory stock setup also had the od top loader in it -- might be a source if your out in the yards looking
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Re: 300 HD heavy duty exhaust manifold

Post #35 by econovan » Wed May 13, 2009 11:24 pm

I've got the offy dual port in now and am looking for prices for a Barry grant 525 JR demon.

Anyone know a good source for new manifold studs for the 300?

Thanks

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Re: 300 HD heavy duty exhaust manifold

Post #36 by AbandonedBronco » Thu May 14, 2009 9:00 am

If you have a local exhaust shop, call and ask them where they get theirs. That's how I found mine. I also converted from bolts, to 100% studs and love it. Made things much easier to put on and take off.

As for the thick, spring washers.... Ford wants $10ea for them, which is $130 for all of them. I haven't been able to find another source, so I just reused the originals.
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Re: 300 HD heavy duty exhaust manifold

Post #37 by econovan » Tue May 19, 2009 10:57 pm

Found 3/8-16-3/4 set screws with allen key at a local fasteners shop.
Went to the kar care muffler shop and asked if I could change my manifolds in his parking lot.
He said ok and two hours later he installed a 40 street series flowmaster single in, dual out muffler using 2.5 inch pipes & chrome tips.

Everything bolted right up to the stock intake and matched the studs and gasket holes.
No surprises other than he didn't have a flange with the matching bolt pattern but found one that was close enough.

Sounds amazing, nice lopey noticable idle from the melling torque cam with a deep tone that fades slowly away when accelerating.
She's breathing alot better now. I'm happy :)

Next step is the Offy dp w. BG 525 Jr.

Cheers
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Re: 300 HD heavy duty exhaust manifold

Post #38 by AbandonedBronco » Wed May 20, 2009 9:32 am

Awesome! That HD manifold looks great on there. :thumbup: :wink:
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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Re: 300 HD heavy duty exhaust manifold

Post #39 by StrangeRanger » Wed May 20, 2009 2:14 pm

That HD manifold is just begging for a J-pipe and a T04. :lol:
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Re: 300 HD heavy duty exhaust manifold

Post #40 by THE FRENCHTOWN FLYER » Wed May 20, 2009 8:21 pm

That looks real nice - but that air cleaner is real restrictive, especially when it gets a little dirt in it. I'd find something larger.
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Re: 300 HD heavy duty exhaust manifold

Post #41 by Craigwell » Wed May 20, 2009 8:27 pm

by krobert56 » Tue May 12, 2009 1:32 pm

saw one on a 1985 e150 on its way into the crusher couple of days ago would have been $15 if i had known what i was looking at - appeared to be a complete factory stock setup also had the od top loader in it -- might be a source if your out in the yards looking


Now THAT has piqued my interest. I have a good friend with an 86 E150, equipped as you speak.. 300 with toploader OD. There were a few of those vans with the 3 sp w/ OD.. I've seen two now.

I'll be sure to take a close look at it's exhaust manifold, and report back.
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Gone but not forgotten: 1976 F250 4x4 300 six, NP435. Dana60/44HD 4.10 Traction Lok, EFI Exhaust, 240 Head

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Re: 300 HD heavy duty exhaust manifold

Post #42 by econovan » Thu May 21, 2009 12:07 am

THE FRENCHTOWN FLYER wrote:That looks real nice - but that air cleaner is real restrictive, especially when it gets a little dirt in it. I'd find something larger.


I know, the intake and carb&cleaner are the next thing to figure out.

I've planned to fab an intake tube coming out of the lid of the doghouse and taking fresh air from the side of the body.
With an inline airfilter...maybe?

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Re:

Post #43 by slaura » Sun Nov 22, 2009 11:38 am

AbandonedBronco wrote:The HD manifold flows very well. It was designed to run on large trucks that kept the 300 a 3000 - 4000 RPMs all day long.

They really flow. I see them on ebay ALL the time, but usually around $200.
They can be spotted easily because the outlet goes straight down, instead of curving towards the rear.




Can anyone tell me what search terms on ebay they used? I've been watching for it for about a month and am thinking maybe its under a different category then I am searching for.

Scott
Scott, New Orleans LA, 300 in an AA (not yet but am working on it)

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Re: 300 HD heavy duty exhaust manifold

Post #44 by Craigwell » Sun Nov 22, 2009 3:59 pm

ahh.. nice thing the topic reply notification. I see that I neglected to report back about the Van i mentioned a few posts up the thread. The 86 E150 I spoke of indeed does NOT have an HD manifold.
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Re: 300 HD heavy duty exhaust manifold

Post #45 by 66 E100 Pickup » Sun Nov 22, 2009 8:08 pm

I haven't seen them recently either, you may want to call Stevens Parts and ask.

Originally, they would not bolt up to the stock intake (two years ago). They were aware of the problem, and apparently did some machine work to make them fit onto the stock. Perhaps they ran out of the HD?

John/Fresno

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Re: 300 HD heavy duty exhaust manifold

Post #46 by shmoozo » Mon Nov 23, 2009 2:40 am

The only source I know of for the 300 Heavy Duty exhaust manifold (or one sort of like it) is Stevens.

Stevens Ford Exhaust Manifolds

Look for the one with part number 300HD.
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Re: 300 HD heavy duty exhaust manifold

Post #47 by PONTIACBIRD93 » Tue Apr 06, 2010 2:43 am

I just bought a HD exhuast manifold from a junk yard and it has the 3 bolt bolt patern where it bolts to the intake. Did they make more than one type?

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Re: 300 HD heavy duty exhaust manifold

Post #48 by Lazy JW » Tue Apr 06, 2010 10:25 am

PONTIACBIRD93 wrote:I just bought a HD exhuast manifold from a junk yard and it has the 3 bolt bolt patern where it bolts to the intake. Did they make more than one type?


Some of them had a four-bolt pattern.
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Re: 300 HD heavy duty exhaust manifold

Post #49 by J.R. » Tue Apr 06, 2010 5:23 pm

StrangeRanger wrote:That HD manifold is just begging for a J-pipe and a T04. :lol:


IIRC the HD manifold is the piece that the late Ak Miller used in his BB6 turbocharger kits that were marketed in the 1970s-early '80s. Ak machined off part of the manifold's outlet & jig-welded a 4-bolt iron flange for the T04 turbo on there, for a very direct flow, as shown in these pics from an earlier thread.

http://www.ckdesign-inc.com/images/Turbo/Manifold1.JPG
http://www.ckdesign-inc.com/images/Turbo/Manifold2.JPG

The full turbo kit contained a water-heated adapter for a Ford or Holley 2bbl in a 'draw-through' configuration, with the compressor blowing into the stock intake manifold.

J.R.
SoCal

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Re: 300 HD heavy duty exhaust manifold

Post #50 by AbandonedBronco » Tue Apr 06, 2010 5:34 pm

That's just fun to look at. Thanks for the pics. :shock: :mrgreen:

I can imagine that the HD manifold would be extremely desirable for a turbo setup. The EFI manifolds, while high flowing, would be a pain due to there being two of them, and curving in different directions. The stock isn't that high of flowing, and curves backwards, which would be a hindrance. The HD is high flowing, and straight, which would allow for an easy to work with base.
1985 Ford Bronco Eddie Bauer. 300 I6. 9.1:1 CR, roller rockers, EFI manifolds and 2.5" exhaust. DUI ignition. 3.55 final drive, 5 speed ZF5. Holley Sniper EFI w/Offenhauser C Intake. 32" BFG KO2 A/Ts.

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