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#307414 - 05/04/09 09:32 AM Headers vs. 70 Manifolds
LL340Rag Offline
master

Registered: 01/28/03
Posts: 4507
Loc: Connecticut
I have a 340 w/360 heads final compression about 9.25. What HP gain would you guess by replacing the factory exhaust with a set of headers?
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#307415 - 05/04/09 09:37 AM Re: Headers vs. 70 Manifolds [Re: LL340Rag]
MLR426 Offline
master

Registered: 08/17/05
Posts: 4779
Loc: ILL
My guess would be 20 hp.

logan426

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#307416 - 05/04/09 09:44 AM Re: Headers vs. 70 Manifolds [Re: MLR426]
moper Offline
I Live Here

Registered: 02/03/03
Posts: 12675
Loc: Columbia, CT
More importantly... what camshaft?
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Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

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#307417 - 05/04/09 10:13 AM Re: Headers vs. 70 Manifolds [Re: LL340Rag]
YO7_A66 Offline
master

Registered: 01/20/03
Posts: 5207
Loc: Indiana
Over the Winter, I swapped out my 70 HP manifolds for the TTi headers (just headers, no other exhaust changes) in my combo listed below. I am still doing some minor tuning to the carb (IFR changes and jetting) so I have not been able to drive the car as hard as I did before this swap, but so far I am very happy with the results.
The off-idle response (torque) is the best part of the swap so far. The car is very responsive in the low range now and over the weekend I found another bonus. With the HP manifolds, the most my converter would flash too at 60mph in third gear cruise was 3500rpms. Over the weekend I noticed that it is now flashing to 3700rpms at 60mph. The swap definately made a "seat of the pants" difference on the bottom end and the flash rpms show some output change too, but I do not have any track information to pass forward to back this up.
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1970 YO7 A66 [Canadian Export] F8 Challenger
340 (SL.P. 226/238@.050,270/288 dur,.538"/.528" w/Yella Terra 1.65 rockers, 9.7:1, 63cc Sidewinders (Bowl Ported),RPM intake, QF SS-750 Annular DP, MSD Street Fire Ign., & TTI's. 727/Dynamic 9.5" 3800, TF-2, & 3:91's

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#307418 - 05/04/09 10:33 AM Re: Headers vs. 70 Manifolds [Re: YO7_A66]
patrick Offline
I Live Here

Registered: 01/20/03
Posts: 16102
Loc: Grand Haven, MI
depending on cam, 10-30HP and 10-30 lb-ft torque....
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1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2006 Inferno Red Dodge Caravan SXT 2011 Toxic Orange Dodge Charger R/T

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#307419 - 05/04/09 03:36 PM Re: Headers vs. 70 Manifolds [Re: moper]
LL340Rag Offline
master

Registered: 01/28/03
Posts: 4507
Loc: Connecticut
Quote:

More importantly... what camshaft?




Comp 268XE
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