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  #1  
Old 08-29-2002, 02:37 AM
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Ausydad Ausydad is offline
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Default 956 vs. 308's

I know the 302 heds are supposed to have the swirl ports, closed chambers, and 1.78/1.50 valves - but what of the 308's? Are they the same but without the swirl ports?? I have a set on a ex-municipal '85 Dippy (no-suregrip, damnit!!) but would like to figure out if they are really worth pulling off or just using the '81 360 heads that I already have with 1.88/1.60 72 cc chamber heads for my tunnel rammed 318. My original setup on Desktop called for 302's to be worked. What do you guys think??
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Old 08-29-2002, 06:29 PM
mr_340 mr_340 is offline
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Default 308s

From the heads I've seen at the Mopar Performance trailer at the Motorplex, the newer 360 castings have a much better short side radius in the exhaust port. This should help on the exhaust flow numbers. I have two casting numbers on these type heads: 4448308 and 4772576.

On the 302s I had years ago, the only swirl effect I could see was the chamber shape. I thought the ports looked the same. Maybe there was a subtle change in the ports.
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  #3  
Old 08-29-2002, 09:47 PM
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rumblefish360 rumblefish360 is offline
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The 308's are said to be swirl port heads. The larger port window will allow for higher RPM operation on a 318. The larger valves also help.
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Old 08-30-2002, 12:51 AM
Crank Crank is offline
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i would rather use magnum heads than 308's they flow much better the valves are better the intake and exhaust ports have a nicer desighn they use stock 1,6 rockers push rods are around 60 bucks and oil threw lifters are 2.50 each 360 amc they boost the compresion over stock heads ,and the mopar duel or single plain manifold is around 250 but eddlebrock is going to pop out some new ones really soon for magnum heads.
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  #5  
Old 08-30-2002, 01:55 AM
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Ausydad Ausydad is offline
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I was under the impression that the 308's were non- swirls. The 318 that they will go on is .060 over (328) with Melling oil pump, reamed passages, Miloden gear drive, MP .024 head gaskets, flattop 10.5 pistons, 296/.557 cam with 106 cl, Edelbrock tunnel ram with twin Holley 450's or Edelbrock 600's depending on trial after motor is in and tuned, Dynomax ceramic headers and 3" pipes with crossover and Hooker mufflers, '65 A833 4 spd trans, and 3:21 gears out back with 315/50/15 tires. Maybe that will help a little. The car is a Duster and will see the streets quite often. I'm looking at the 308's as I already have them and cash is tight!! Porting is no problem and will be done on either head. I'm looking for flow and compression...... ramble, ramble. I guess I should go to bed to start again in about 5 hrs. Later,
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  #6  
Old 08-30-2002, 02:13 PM
mr_340 mr_340 is offline
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Default Mismatched Components?

I'd rethink that combo a little if I were you. I'd forget about the tunnel ram setup and look at the Performer RPM intake with a single 750cfm carb. The cam is probably too big with only 3.21 gears. You probably should either look at more gear (4.10s), or detune the engine to work with the 3.21s. I think the 308 heads will work fine either way you go.

Check out some dyno combos on the Edelbrock and Comp Cams websites. I'd pick one of them and follow it. I think you will like the results better.
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  #7  
Old 08-30-2002, 05:49 PM
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lenweiler lenweiler is offline
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Gripe What, what, what

1. The 308 and 576 is in fact the same head. The 76 is just a new number. I have both.
2. They are both swirl port and sold under the same part number.
3. They both port the same. The porting templates sold by MP are good for both.
4. There are advatages and disadvantages to both the commando and magnum head. I prefer the commando since it has a more regid valvetrain, and is a good copy (albeit water-down version) of the W2's.
With time and a little work (who am I kidding?) all these heads make good power.
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  #8  
Old 08-30-2002, 10:53 PM
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Ausydad Ausydad is offline
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I agree with changing the rear gears to help match the combo. Just waiting to finish paying for this stuff before I can look for the sure grip 60 or 8.75 to put gears in. It's all time and budget, so I'm going slow for once!!
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