I am planning to build a 408 for my 70 challenger, I have the choice between using a set of factory J heads, or a buddy of mine has a set of w2 heads, intake, headers. What is the difference between w2 heads and the factory X, or J heads
Whats the big deal?
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Plymouth 65
I'll be in the shop
Main difference is port design and flow. W2's are far better heads but you have to use specific rockers, intake, and headers. 65
If I had a choice, W2's for the win. Are you building for performance?
Dartswinger70
Well-Known Member
W2s were the Mopar performance race head right? the X and Js were the factory street performance head no? Point being one was mass produced for a street car other was offered as a race part.
aaronk785
Well-Known Member
W2s. Especially for a hot 408.
gzig5
Well-Known Member
If he's go the rockers for the W2's, that is a no brainer for a high performance build. W2 vs X/J stock out of the box have an advantage of 30-50hp depending on the combo. With full effort porting, the W2 advantage goes to 100+hp over the X/J heads. I'm spitballing the HP numbers, but the W2 is a significantly more capable head. You just have to have all the correct support pieces to run them, and someone that knows how to take advantage of the ports. The X/J head even with full porting can't feed the air that a 408 with big cam can use. They still can make a fun and torquey motor though for a street oriented car.
If you give more details on the car such as trans, gearing, intended use, etc, you'll get more accurate feedback.
If you give more details on the car such as trans, gearing, intended use, etc, you'll get more accurate feedback.
they were just factory heads, that's it. some of the J's came with bigger 2.02 intake valves.
The difference is 100 HP and a way more valuable and capable combination.
middleagecrisis
Well-Known Member
Why limit the choice between a factory production head and the W-* series of heads that require the high dollar one-off valvetrain? Aftermarket heads (iron or aluminum) offer a substantial HP increase and most street versions can utilize factory parts if you wanted to go that way. Even upgrading valvetrain would seem to be cheaper to go the aftermarket route.
Ironmike
Well-Known Member
My thought is, unless they are ported by a pro and intake to match, you won't notice much. That is, unless you have the cam and gears to take advantage of them.
Typical example: 408 with mild street cam and J heads.....420 HP
As above with OOTB W2"s.....................440 HP
Now. As many have stated above, if you're going for a big number and ya have all the crap to go with them, take the W2's.
Typical example: 408 with mild street cam and J heads.....420 HP
As above with OOTB W2"s.....................440 HP
Now. As many have stated above, if you're going for a big number and ya have all the crap to go with them, take the W2's.
Plymouth 65
I'll be in the shop
Well with a good lower end and W2 top end you will have just about the best combination to be had IMO. 65
gzig5
Well-Known Member
What do you want to do with it? If just street cruising and going to shows, then stick with the X/J head with a good rebuild. If you are wanting to go fast and finishing out the W2 is in your budget, then go for it. You'll need a 3500+ stall converter to support any decent cam. Once setup, the W2 isn't any more maintenance than any other head. If well ported, the W2 will really shine with a solid roller cam, but that adds some cost for the lifters and distributor drive gear. Just comes down to what you want to do and how much you are willing to spend to do it right.
Another vote for W2 here. I wanted something different on my 414 and wanted it to look period correct. My engine builder sold me a set that he had laying around also a set of Jesel 1.7 rockers to go with them. With some porting and a custom solid lifter cam he was able to make 571 hp/529 tq. Should be fun in front of a four speed in my Duster.
MOPAROFFICIAL
If it has tits, it's a liabilititty.
Use the larger port w2 head.
Randomness....Something to notice is some people may say to use a worked 302 casting head on a 360... but those same people will never say to use a worked j head with a 4".
The reason is up for debate.
I think probably
302 head peeps are usually velocity worrywarts and don't overly care about hp, but ask them what velocity is needed they never can answer but know you got to worry about it though
People building a 4" stroke motor generally are wanting 475-625+ hp.
Something to keep in mind with W2s is that will want a lot of cam to work well . You may not like the street ability of such a build . I run ported W2s on a 408 with a 246/250 on a 108 with .648 lift cam and I only make about 525 hp and 495 ft/lbs . If I would have used a 260+ @ .050 cam I probably would have been closer to 600.
And they want lots of compression.
You will also need custom pushrods , big (expensive) headers , 3” exhaust , big carb (800 + cfm ) , 3/8+ fuel line , HD driveshaft and 1350 ujoints , HD axles and probably upgrade suspension.
If this is a street car you would probably be better off running ported stock or aftermarket heads . If it’s a race care the W2s will make some serious hp.
And they want lots of compression.
You will also need custom pushrods , big (expensive) headers , 3” exhaust , big carb (800 + cfm ) , 3/8+ fuel line , HD driveshaft and 1350 ujoints , HD axles and probably upgrade suspension.
If this is a street car you would probably be better off running ported stock or aftermarket heads . If it’s a race care the W2s will make some serious hp.
9secRR
Well-Known Member
There is zero comparison between the X/J heads to the W2. Not even in the same category so go with the W2 and don’t look back. You can find good deals on rockers, they are out there.
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