Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1991527
01/15/16 09:42 PM
01/15/16 09:42 PM
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Joined: Jun 2006
Posts: 5,163 CT
GTX MATT
master
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master
Joined: Jun 2006
Posts: 5,163
CT
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It really depends on how well they flow, bottom line. You also forgo the opportunity to build quench easy, but with your domed pistons it sounds like it wouldnt matter. If you change the springs yourself you'll be in them for about 650-700 bucks. If the springs will work with your cam itd be a better deal. Being a 383 it will be sensitive to the size of the combustion chamber too, how far below deck are the pistons and how big are the domes? They will need a fair but not drastic amount of milling to get them down to the 80cc most aftermarket heads are. Also any aftermarket head will have greater potential max ported va the iron heads.
Intake depends on the rest of the setup, cam, gears, headers/manifolds, etc.
Last edited by GTX MATT; 01/15/16 09:43 PM.
Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1991580
01/15/16 10:57 PM
01/15/16 10:57 PM
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Joined: Oct 2011
Posts: 559 Idaho
LaRoy Engines
mopar
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mopar
Joined: Oct 2011
Posts: 559
Idaho
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Quick, read the post from yesterday at 1:49PM, its dead on.
The one about Mopar porting templates
Mill which heads? What service is this engine destined for? What fuel? Piston number? Deck height? Cam?
Input. Input!
Last edited by LaRoy Engines; 01/15/16 11:14 PM.
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1991615
01/15/16 11:43 PM
01/15/16 11:43 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Iron heads.. prone to cracks... unknown porting.. weight factor... my pinion.. check out the alum heads out there to see if you clear the pistons and the quench would be and if they fall into the compression range you want... also check the valve to cyl wall clearance if they clear
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1991921
01/16/16 01:38 PM
01/16/16 01:38 PM
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Joined: Jan 2003
Posts: 10,010 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,010
Frostbitefalls MN (Rocky&Bullw...
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I agree with going new aluminum heads. You can get more power out of them, reliability is better, (old iron, subject to cracking) and performance is usually as good or better than ported iron heads in out of the box condition. Is the 650 lift cam the 290 at .050 cam?
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1991931
01/16/16 01:47 PM
01/16/16 01:47 PM
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Joined: Jan 2003
Posts: 4,274 Morrow, OH
markz528
master
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master
Joined: Jan 2003
Posts: 4,274
Morrow, OH
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For $895 I think the aluminum heads are a no brainer. I saw the sidewinders yesterday at Todd's place and I have to say I'm quite impressed for the money. Actually bought a pair for my GTX build. I got a great flowing set of 906 heads. 3 major unrepairable cracks in them.......... http://www.mopartsracing.com/parts/Sidewinder.html
Last edited by markz528; 01/17/16 01:34 AM.
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1992093
01/16/16 06:04 PM
01/16/16 06:04 PM
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Joined: Jan 2003
Posts: 14,504 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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For any kind of "race car" the aftermarket heads just make more sense. For a milder street/strip combo, I think the smaller runner volume and stock valve sizes play well on a 383, and would likely be my preference. Of course, this is in part because I don't have to pay to have stock heads reworked. There are pretty few applications where using reworked stock heads is the better choice......it's usually a situation where they are manditory(class rules), or it's a high level restoration.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: ported 906 heads or aftermarket
[Re: fast68plymouth]
#1992106
01/16/16 06:36 PM
01/16/16 06:36 PM
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Joined: Jan 2004
Posts: 8,285 fredericksburg,va
cudaman1969
master
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master
Joined: Jan 2004
Posts: 8,285
fredericksburg,va
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For any kind of "race car" the aftermarket heads just make more sense. For a milder street/strip combo, I think the smaller runner volume and stock valve sizes play well on a 383, and would likely be my preference. Of course, this is in part because I don't have to pay to have stock heads reworked. There are pretty few applications where using reworked stock heads is the better choice......it's usually a situation where they are manditory(class rules), or it's a high level restoration. Agree, Any street car can use the 452s with unleaded seats and never have a problem. Never seen a bb head cracked unless it was hogged out so far you could see the water circulating. Street only, use cast head, racing, best aluminum head you can get. Don't put good money to bad.
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1992113
01/16/16 06:50 PM
01/16/16 06:50 PM
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Joined: Jan 2003
Posts: 6,988 Warren, MI
Jerry
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master
Joined: Jan 2003
Posts: 6,988
Warren, MI
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never spend a dime on cast iron heads. even if you want a little more performance its better to get the aluminum. they already come with 2.14/1.81 valves, thinner guides, good valve seats, usually come with springs that are ok.
if you have to use the cast iron and put in guides, put in hard seats, upgrade to new valves, new keepers, and retainers, and port and polish you will be way over what a set of aluminum heads will cost you. I think the 440 source ones looks cast on the outside, so paint them and they look stock. only you'll know the difference.
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Re: ported 906 heads or aftermarket
[Re: moparmafia]
#1992212
01/16/16 09:45 PM
01/16/16 09:45 PM
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Joined: Feb 2005
Posts: 20,184 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,184
PA.
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I went 9.80's 22 years ago in one of my old .030 over trw piston 440 engines with a set of 906's that finally cracked after years of use. They are still setting here in my shop and I could redo a set and I still wouldn't do it with all the cheap aluminum head choices available
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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