Head valve size questions, Buying new heads
#2498988
05/22/18 11:22 AM
05/22/18 11:22 AM
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Joined: Feb 2005
Posts: 276 Janesville, WI
polarconvert
OP
enthusiast
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OP
enthusiast
Joined: Feb 2005
Posts: 276
Janesville, WI
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Hello Guys, I have a solid stock 383 bottom end, running a stock cast iron 4 barrel intake,Mopar performance roadrunner 280 474 110 purple shaft factory non hp exhaust manifolds, stock single exhaust, I plan on purchasing a new set of CC 516 heads, 2.08 x 1.74 valves from Aerohead racing, Besides ordering the hardened seats. Should I spring for the larger 2.14 x 1.81 valves for only $50 more or would that be a waste? The motor is going in my 65 C body convert, automatic, 323 rear. Just looking for more torque out of a stock looking motor.
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Re: Head valve size questions, Buying new heads
[Re: polarconvert]
#2499001
05/22/18 11:46 AM
05/22/18 11:46 AM
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Joined: Aug 2006
Posts: 2,505 God's Country Maryland
GODSCOUNTRY340
master
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master
Joined: Aug 2006
Posts: 2,505
God's Country Maryland
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With your set-up all you need are the 2.08/1.74 valves. 516 heads with 2.14/1.81 valves will be shrouded by the combustion chamber and the top of the bore. Now if that was a 440 the larger valves would be nice due to the larger bore. You'll get more torque out of the smaller valves with your set-up.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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Re: Head valve size questions, Buying new heads
[Re: GODSCOUNTRY340]
#2499010
05/22/18 12:24 PM
05/22/18 12:24 PM
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Joined: Jan 2003
Posts: 13,362 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,362
Marion, South Carolina [><]
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With your set-up all you need are the 2.08/1.74 valves. 516 heads with 2.14/1.81 valves will be shrouded by the combustion chamber and the top of the bore. Now if that was a 440 the larger valves would be nice due to the larger bore. You'll get more torque out of the smaller valves with your set-up. I'd change the entire exhaust system too. Let it breathe.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Head valve size questions, Buying new heads
[Re: polarconvert]
#2499029
05/22/18 01:09 PM
05/22/18 01:09 PM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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Just looking for more torque out of a stock looking motor. As said I would get some 68-70 HP ex manifolds & dynamax (sp) turbo muffs with in addition glasspacks alongside the rear leafs. those Aeroquip heads are a mass produced item & there have been bad reports (but the internet is the complaint dept so we do get the bad experiences, just sayin). Are your current heads OK? if so I would leave em be & possibly swap the cam (what is your SCR) & get a good torque converter. Some aluminum stealths might be a cost wise alternative (again what shape are your current heads) & you might eventually get a 400 block/440 crank for 451 cubes!. when done be sure to dial in your dist subsystems in order. EDIT Mandrel bends 2&1/2" system/X pipe.
Last edited by RapidRobert; 05/22/18 01:20 PM.
live every 24 hour block of time like it's your last day on earth
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Re: Head valve size questions, Buying new heads
[Re: polarconvert]
#2499090
05/22/18 03:11 PM
05/22/18 03:11 PM
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Joined: Jan 2003
Posts: 14,496 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,496
So. Burlington, Vt.
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If your local shops do quality work, having the originals refurbished for $530 might be the smarter choice.
IMO, the Aerohead rebuilt heads are better looked at as being a "parts kit", where some tweaking might be required.
If you're looking for more grunt, I'd look at a smaller cam too.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Head valve size questions, Buying new heads
[Re: fast68plymouth]
#2499243
05/22/18 10:58 PM
05/22/18 10:58 PM
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Joined: Feb 2005
Posts: 4,313 Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,313
Prospect, PA
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If you're looking for more grunt, I'd look at a smaller cam too.
This. That cam is so not right for your exhaust system, and your goal. I would go down a couple of cam sizes. You are at about 230° @ 0.050". I would look for something less than 220°.
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Re: Head valve size questions, Buying new heads
[Re: polarconvert]
#2499303
05/23/18 01:06 AM
05/23/18 01:06 AM
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Joined: Jul 2011
Posts: 956 Chicago
PurpleBeeper
super stock
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super stock
Joined: Jul 2011
Posts: 956
Chicago
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I have to agree with these other posts. If you are dead-set on a single exhaust & want more low-end torque, then rebuild the iron heads you have, "maybe" some minor port work + hardened exhaust valve seats for sure. A smaller cam will give you better off-the-line acceleration too in my opinion.
70 Roadrunner convt. street car
440+6, NOS, 4-spd, SS springs
'96 Mustang GT convt. street car
'04 4.6 SOHC, NOS, auto, lowered
"Officer, that button is for short on-ramps"
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