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Discussion Starter #1
I have a 65 FB with the original 289. It has a genuine Shelby high rise intake. (Cobra in small letters on pass. side) I am looking at rebuilding the top end. I've been looking at the Edelbrock top end kit #2091. Kit comes with heads, intake, cam etc.

My question is will the Edelbrock intake make a big difference with the matching heads, cam etc? Or should I keep the Cobra intake and buy the heads and cam separately?

The Cobra intake is a cool piece, but I'm not married to it. If there is reasonably priced stuff out there that will work better, I'm interested.
 

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The Cobra is an excellent manifold, within about 3% the same flow as the Edelbrock Performer RPM manifold. That's a difference so small as to be not worth the effort to swap them. Pretty good job for guys who didn't even have computers to design it. Plus it'll make the Shelby guys crazy you have the real deal on a Mustang.
 

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even the reproduction Cobra intake works better than the original one. If I were in your shoes I would buy the heads, cam, intake & whatever else you are wanting separately. If you want to keep the peroid look there are plenty of iron heads that come ported and ready to go, and you can sell the Cobra intake to help finance the whole project. Replacing it with a repro Cobra intake or something more modern looking.

I love the aluminum heads, and the many choices offered these days, but for most people, a set of iron heads will do the job, and look stock if that matters.

Z.
 

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If you sell it on ebayor elsewhere you can get double or tripple of the money a used Edelbrock RPM or a Professional Product AirGap costs. The difference you can spend to a better ignition or carb.

Name doesnt make power
 

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Discussion Starter #5
The Cobra is an excellent manifold, within about 3% the same flow as the Edelbrock Performer RPM manifold. That's a difference so small as to be not worth the effort to swap them. Pretty good job for guys who didn't even have computers to design it. Plus it'll make the Shelby guys crazy you have the real deal on a Mustang.
If that intake is really that efficient I'm keeping it for sure. I like the period correct stuff especially when it works great!
 

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If you sell it on ebayor elsewhere you can get double or tripple of the money a used Edelbrock RPM or a Professional Product AirGap costs. The difference you can spend to a better ignition or carb.

Name doesnt make power

Name doesn't make power. So why pay big money for a Shelby, K code or Boss 302? Anyone can get a used recent car with 300+ HP and great handling for around $10,000.
Guess we're sentamental fools!

Slim
 

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It probably depends on what the rest of the car is like and what floats your boat. If it is a period correct car in its look, I would keep the cobra intake. If the rest of the car is after market stuff and you don't hold a high value on the period stuff, sell the intake on ebay and make some bucks.
 

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like the cobra intake look? sells yours for $800+. Buy the repro Cobra manifold which flows better over a greater rpm range for $400 and change. Take the $400 difference and spend it on the rest of parts list.

Z.
 

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Discussion Starter #9
It probably depends on what the rest of the car is like and what floats your boat. If it is a period correct car in its look, I would keep the cobra intake. If the rest of the car is after market stuff and you don't hold a high value on the period stuff, sell the intake on ebay and make some bucks.
My car is a GT350 replica. Supposedly lots of Shelby parts. Intake, carb, seat belts, Cragar wheels, dash tach pod, steering box? etc. Story was the parts came from wrecked car #93. Who knows!

I understand that most of it can't be documented, but I kinda like thinking that it's the real deal. I didn't overpay for the car so it's not a big deal either way.
 

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While I would usually defer to anything 22 posts; from a performance point of view, if its a high rise open plenum (big single cave under the carb it may not match your heads if you go performer heads. It will like the performer RPM or victor Jr heads better. If it is a dual plane (Probably not) then you will like it better for everyday driving. Open plenums are made for wide open throttle, the dual plane is made for throttle response any time you punch it. Dual planes are more fun to drive around town and most of the time but you may give up a little at wide open throttle and high rpms.

Kinda depends on what you want to do and how much you like the COBRA on the side. I can certainly understand liking the COBRA on the side...

Good question...

M
 

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I have seen charts on the manifolds, and the Performer RPM is a few percent better at fuel distribution around 6000 rpm than the Cobra. I don't exactly spend a lotta time at 6000 rom. The Cobra is a dual-plane high-rise. Excellent street and track performance. Factory installed on 65-68 GT350.

 

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I had an S1MS intake on my GT from around 1986 to 1996, bought it for
$230 and sold it for $750. A guy with an early Cobra was dying to get it.
No matter who cast those early manifolds (Offy, etc.), the amount of
flow isn't the issue, the distribution of the flow is.....
The corners run lean, particularly cyl #4 and cyl #8.
We discovered this on a Superflow dyno when I was at JBA in the late
80's.
Cobra Automotive (and others) expend lots of energy tweaking the
original manifolds to make them "just right."

That distribution issue is one of the things Vic's guys addressed when
they did the Performer RPM intake.
 

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The rarity of the S1MS makes it a big draw for collectors. The later S2MS, at least two versions, and the S7MS, not so much. Did you ever compare them?
 

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Unfortunately no. The SIMS intake was a NOS one in the box that we
"acquired" for the Cobra guy in England. The engine ran him $17,000.....
even the wood shipping crate we had custom made was pricey at $550.
 

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i bought a buddy bar shelby 351W intake for $200.00 last year at the pomona car swap meet. the guy had 2 along with other ford performance parts. i cant see that 289 intake being worth more then $200-$300 tops unless it came from the factory on a 65-68 shelby. there were some test done on that intake vs the edelbrock performer and performer rpm and that factory cobra intake had better overall flow numbers. the airgap beat it out but that cobra intake is much better for a street car. i say keep it and use it. i put the shelby intake i have on my 392W torino street engine. i use an airgap on my hot rodded 392W mustang engine. those cobra/shelby were available over the counter back then.
 

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Edelbrock once thought enough of the Cobra that they copied it.

 

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I have seen charts on the manifolds, and the Performer RPM is a few percent better at fuel distribution around 6000 rpm than the Cobra. I don't exactly spend a lotta time at 6000 rom. The Cobra is a dual-plane high-rise. Excellent street and track performance. Factory installed on 65-68 GT350.
That said, I would definitely run it - never hurts to add a little performance history to the mix. Its like seeing "Offenhauser" on a flathead, guaranteed to spice up the hoods-up BS sessions...

M
 

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Discussion Starter #18
OK, I've decided to keep the Cobra intake. 22GT, could you recommend heads and a cam? No drag racing, maybe an autocross or 2 and the rare track day. Lots of spirited country road driving. The goal is 300+ HP.
 

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Too easy. Perfect example is a guy near here. I gave him my usual recommendation for the type of driving you describe.

• Edelbrock 600 cfm (you could use a Summit, which might be better, but I've never used one)
• Edelbrock Performer RPM intake
• 289HP air cleaner
• Stock distributor, tuned to BOSS 302 specs
• Stock iron 67 heads, fitted with screw-in studs, and port-matched (he did it himself) exhaust ports
• C9OZ-6250-C hydraulic version of the 289HP cam

No other modifications. Engine was run-in on a dyno, and turned 323 hp.

 
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