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Author Topic:   ford heads
Big Bird
Dirt Full Roller

Total posts: 27
posted October 06, 2002 08:12 PM
Can somebody tell me witch would be better the cast roush 200 heads or gt40 heads or the n351 on a 2 2 barrel

dode
Dirt Freak

Total posts: 417
posted October 06, 2002 09:39 PM UIN: 13209501
how much displacement, and what are the rules of the class?

John

outlawstock17
Dirt Forum Champ
Total posts: 620
posted October 07, 2002 06:08 AM
N351.....clearly the best head, hands down.

KPLugnut
Dirt Freak

Total posts: 408
posted October 07, 2002 06:41 AM
I will agree there, but there is also the newer N352 now, that has some improvements over the weak spots of the N351.
Either way, the N heads are the way to go, even for a 2bbl motor.

KPLugnut

d4490
Dirt Maniac

Total posts: 113
posted October 07, 2002 11:58 AM
I would use the new N352 heads for a 2 barrel application. The ports are a little smaller than the N351, but flow the same cfm. This means more port velocity and more power for the 2 barrel.

Tom Asmus
Dirt Freak

Total posts: 219
posted October 07, 2002 05:48 PM
I agree 351n heads are the way to go! I wont run another set of stock production heads! 351n heads without a doubt!!!

modfan
Dirt Full Roller

Total posts: 27
posted October 10, 2002 06:46 PM
I'm wondering if anyone has ran the new roush heads and how well they liked them?

outlawstock17
Dirt Forum Champ
Total posts: 620
posted October 10, 2002 08:25 PM
hey KP, i read the article on the new "N352" heads. performance wise, the only improvement i see is if you're limited to an 1 5/8" header and can't port match the intake runners. am i wrong? i'm glad they added some meat in the intake bolt holes. i ruined the first one i had when i torqued down the intake manifold. i like the weight savings of the the new head, but i still like the bigger ports of the earlier head....

KPLugnut
Dirt Freak

Total posts: 408
posted October 10, 2002 10:46 PM
I agree on the intake bolt hole bosses. As for the performance gains, I think maybe what they were more targetting by making the 352's is the guys who are limited to 2bbls. Those huge runners in the 351's are great for big tracks and big carbs, but tiny 2bbl classes had a harder time getting the motors to come up off the corner as quick as the litte Chevy's that spin up faster.
So what they did was make those changes to speed intake charge velocity and on the exhaust side, the changes aid in scavenging that is further benefitted by the use of 1 5/8" headers for more torque off the corners.

Either way, tho, I think with either head, they are the way to go for the windsor-based ford's.

KPLugnut

ford5
Dirt Freak

Total posts: 298
posted October 11, 2002 07:53 AM
we had a street stock car here we ran this summer, and last yr we had a 396 windsor with 69\70 windsor heads on it that i had done pretty massive modifications to, and then the driver had a windfall of money come in from one of his sponsers LOL anyhow, we got a set of roush 200 heads complete ready to bolt on, we installed them and raced the 2nd half of the season. in conclusion, i would say we did not notice a tremendous amount of difference. we did have 1 and5\8ths headers too. and that is another issue with those heads, the headers we had did not leave any room for the spark plugs wires. we had a hard time getting the wires to not burn off, causing several poorer finishes! not a good thing!!we finally 'made' a set work and dented the header pipes to clear better (something that was not a problem with the stock heads due to plug location\angle) i never dynoed my motor before and after, but i seen the results on the track, maybe they would be better if they were ported\polished?........my 02 cents ford5

outlawstock17
Dirt Forum Champ
Total posts: 620
posted October 11, 2002 02:51 PM
hey ford5, i had the same problem with my "N" headed 393. some of the plug wires were getting hot and would fail after a few races. there is a shorter plug available. it's the autolite AR135. i used this plug with heat treated fiberglass boot protectors. it worked great. i just bought a set of howe crossover step headers made specifically for the "N" head and there's a ton of room with them. goodbye melted boots and expensive boot protectors..........hello melted valve covers and melted driver.....LOL

d4490
Dirt Maniac

Total posts: 113
posted October 14, 2002 10:29 AM
Hey Big Bird, you never stated your track rules. Can you run headers or do you have to run stock exhaust manifolds? If you have to run stock manifolds, kiss the "N" heads good-bye. The bold pattern on the "N" head is wider than the stock bolt pattern. The Roush heads have a dual pattern that will work with stock manifolds and headers. The gt-40p heads require a different exhaust manifold (Explorer) due to the placement of the spark plugs.

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