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Author Topic:   Roush 200 or N351/N352 heads
d4490
Dirt Maniac

Total posts: 113
posted January 13, 2003 09:09 AM
Looking into these heads for my stroked 351W(396 c.i.). The flow numbers seem to be very close to each other. For the money, it seems that the Roush head would be better. The N351/N352 heads require a different intake rocker arm, offset pushrod location. The Roush head has 200cc intake & 64cc exhaust ports. The N351 has 197cc intake & 78cc exhaust ports. The n352 has 189cc intake & 75cc ehaust ports, but flow the same as the N351 heads.

Has anyone ever ran both heads, and what head was better?

Is the extra money required to get the "N" heads to work worth it?

Any dyno numbers out there for these heads>

ford5
Dirt Freak

Total posts: 298
posted January 13, 2003 06:37 PM
for the difference in money, i'd stay with the roush 200 heads, i've had both and never could see that much difference on the "on track" performance of the 2. i have seen pushrod bind issues with the older N heads too, remember that the N head requires different header flange too.
In all actually, i have had good luck with the old C9 windsor castings too. but if you have a no port\polish rule at your track that rules them out. remember also that the N and roush heads weigh a bunch more than the C9\D0 castings.........ford5

outlawstock17
Dirt Forum Champ
Total posts: 620
posted January 13, 2003 07:28 PM
no contest... N351 for a 4 bbl. engine and N352 for a 2 bbl. engine. the N head is a 10 degree design and you can angle mill it a bunch to make it even better. it's not just about flow, it's also about efficiency. the N head will make more power with less timing and will burn less fuel in the process.

i've run a 393 with the N heads for 2 seasons with a "dinky" little solid lifter cam on gasoline against 434 chevrolets with iron eagle heads, roller cams and alcohol. they can hardly beat me down the straights. sometimes they can't.

the pushrod bind issue ford5 is referring to doesn't exist if you use the heads on a 9.5" deck 351w block. a 8.2" deck 302 block is where you can run into trouble. it can be corrected with an offset lifter(roller) or a die grinder in the pushrod holes on the heads.

one more thing.....don't turn this stroker combo over about 6500 rpm or it could get ugly.

[This message has been edited by outlawstock17 (edited January 13, 2003).]

Dirt-Tracker
Dirt Full Roller

Total posts: 60
posted January 13, 2003 09:12 PM
If your running on a 3/8 or smaller get a 347 and save about 70 lbs. Then get it geared right about 7600 rpm and wave at the big chevys as you fly by them!!!

------------------
"Somedays your the dog, and somedays your the fire hydrant!!!"

www.geocities.com/albertson28racing

Dirt-Tracker
Dirt Full Roller

Total posts: 60
posted January 13, 2003 09:13 PM
Oh Yeah......thats just my opinion.

------------------
"Somedays your the dog, and somedays your the fire hydrant!!!"

www.geocities.com/albertson28racing

d4490
Dirt Maniac

Total posts: 113
posted January 14, 2003 06:44 AM
Outlaw, have you ever run the Roush heads or the old World Products head?

ford5
Dirt Freak

Total posts: 298
posted January 14, 2003 06:59 AM
the pushrod bind....does come in to play on the 9.5 blocks also.......i know, been there and had that LOL yes you can fix it with a dremel and by loosening the guide plates and shuffling them around a bit. what i am saying is, the extra money and hassle to be able to run the N head and given the extra weight, i never run them here, you will not be competetive in the mods here with them vs aluminum. and in the street stockers here you will have a hard time running with the 434's out there. yes there are some, and we also have unlimited carbs here. we raced a 396 windsor with roush heads all yr and won a few, but generally was outrun by a bigger SBC (434) but that's the way it goes. so my point is..if i gotta run better stuff than that to win more, i might as well bump my driver\friend up to the mods, where at least it pays more HAHA my 02 cents worth ...ford5

outlawstock17
Dirt Forum Champ
Total posts: 620
posted January 14, 2003 08:03 AM
dirt-tracker, i like those little 347's too. i've got one in my street stang with trick flow heads and a roller cam.....it'll scoot!

d4490, no i haven't run the world heads. they are the same design as the factory heads. 23 degree. there's a reason why ford replaced their old sportsman head(world/dart) with the new sportsman head(N). the N head is better.

ford5, i run the 1996 cast date N head. i had no problems with pushrod alignment on a 9.5" block. if you're running iron heads against aluminum heads, there's no doubt you're in trouble. try the edelbrock victor. you can use your same headers and intake.

to all, no disrespect intended to you guys. we all have opinions and most of them differ. i was just stating mine......the important thing is we all race fords and need to try to help each other.

if you go the N351 route, towers & harwood in kansas has some aftermarket parts that will make your N head assembly a little cheaper to build. you don't have to buy all the ford parts anymore.

[This message has been edited by outlawstock17 (edited January 14, 2003).]

d4490
Dirt Maniac

Total posts: 113
posted January 14, 2003 11:51 AM
Outlaw,
How much H.P. & torque are you putting out of that 393?

I got an email from Pro Topline that they are now making Ford heads in cast iron with the same port cc's and valve sizes as their chevy heads. These heads require headers due to the spark plug location has changed.

outlawstock17
Dirt Forum Champ
Total posts: 620
posted January 14, 2003 02:44 PM
d4490, that's a good question. i'd like to know myself. based on some of the other guys' dyno numbers that i've raced against, my guess would be 500-550 hp, maybe a little more.

i run a conservative engine though, flat tops and a mild solid cam. 6600 rpm max and it lasts forever. i read an article somewhere, can't remember exactly where, but they had a full boogie 408 with N heads and a roller cam making 750+ hp.

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