i was looking at these intake manifolds.
http://www.autopartswarehouse.com/pr...ntake_manifold

but some of them say 4.7L or 6.4L. how do i know which one mine is? osrry im only 16 and dont know much about cars yet. im trying ot learn

btw my car is a 1967 mustang and it was a 302 blocked into a 347 stroker if that helps

 

Since you selected a 67 Mustang on that site, it is only showing the stock engines. 4.7 litre equates to the 289 cubic inch. And further, the 289 intake manifold fits the 302. Therefore, you should look at manifolds for a 4.7L on that particular site for your 347 stroker.

Hope that helps.

 

I had a 289 Performer intake on one of my 302s and I loved it. lol just my 2 cents.

 

alright so both 289 and 302 would fit my engine?

i wasl ooking at this one.

1967 Ford Mustang
Intake Manifold
Brand: Edelbrock

Performer RPM 302, Intake Manifold, Designed For Great Top End Power With Good Throttle Response, High Rise, Dual Plane, Non-EGR, 1500-6500rpm, Air-Gap 302, Cast Finish, Recommend FelPro Gasket PN[1250] For Manifold Gasket

http://www.autopartswarehouse.com/pe...p;brandid=4130

7th one down

 

you won't see great performance out of it. Idle quality also may not be too great. I'd recommend for you, sense you're also new to this, the regular Performer. I got mine from Jeg's who had the lowest price at the time. The Performer has better low end performance where as the RPM is better top-end performance.

 

I have to disagree with you on that. I have run the rpm manifold with very good results. As I and most engine builders I know say...1500-6500 vx idle-5500....how much time do YOU spend BELOW 1500 rpm.......not much.

 

i'd have to agree with mike here. i ran a RPM and love it. i will say that when i cut down the center divider (think of the airgap) i lost some on the bottom.

from what i see about the new weiand action plus intake, it seems like its an even better choice for a streetable 289/302/347

*edit* the weiand part number im referring to is the 8124, says idle-5500 but even their ad claims power increases over the edlebrock performer up to 6000 and if you look at it, it looks more like a RPM than a performer..... so i'll betcha it'll run right up to 6500-7000 and still be making good power

 

It's not that the RPM makes the same power from 1,500-5,500 as the Performer but runs better up top, but they're matched to other parts. If you use an idle-5,500 cam with a 1,500-6,500 manifold, you'll lose power pretty much everywhere except above 4,000-5,000rpm or so(depending on build)when compared to using an idle-5,500 manifold with an idle-5,500 cam. An RPM manifold is bigger than most people need, even that Weiand Action Plus or the regular Edelbrock Performer will make good power up to 6,000rpm(they list them as 5,500 cuz that's where they make BEST power, but with proper part selction power falls off so slowly that at 6k you're only making a few hp less than at 5,500), and most people don't really have engines that make enough power past 6,000rpm to justify a bigger manifold. Why sacrafice average power from idle-5,000rpm just for a few extra peak hp? On a race car I can understand doing that, but not on a street car. Match all the rpm ranges of all the parts with each other, if you use a cam that's listed as going to 6,500rpm then yeah, you may want to run the RPM manifold, but even then your average power with either manifold may be the same. It's the total average power that matters most and not peak. Peak power numbers don't mean squat, that's why you need to match the combination together and use whiched manifold will work best for your application

And on a side note, the new Action Plus from Weiand(8124) is listed as idle-5,500rpm, but is actually a fair bit bigger than the Edelbrock Performer, and nearly as big as the RPM(plenum almost as large, sits nearly as tall etc). It's a pretty beefy manifold for it's class, and I run it on my 302with a 570cfm carb and it'll pull past 6,000rpm without falling off, at least notenough that I can even notice it. I use it because I do most of my driving under 3,500rpm

 

OK, now I have also heard and read that the RPM is the superior intake. While we have this thread going, let's compare the RPM to the Weiand Stealth. If you were building the top of your engine and had a myriad of choices for a carburetor, which one would you buy and why? Make them both dual plane.

 

I've seen the Stealth do some pretty impressive things. I believe they used it in the Car Craft build on a stock long block 302 with AFR 165's and the stock cam, and on an engine dyno put out around 400hp at 6,100rpm(someone can correct me on this if I'm wrong, it's been a while since I read it). I think the RPM is so popular because for a long time there wasn't really a good low rpm performance manifold. There was the older Weiand Action Plus and the Edelbrock Performer, but they were little better than stock 4bbl manifolds, they were just aluminum(though there is the stock 5.0 4bbl manifolds that were aluminum), so the RPM was chosen, or the Weiand Stealth, because the slight sacrafice in bottom end power was totally acceptable for the reasonably decent gains in the mid range and up top on a performance street car.

With the new Action Plus there is now a manifold that "fills the gap" between the older low rise dual planes and the RPM/Stealth, and is a better manifold for street use in most cases(I believe it's also the first manifold for street use that was designed using computational fluid dynamics that's used often in cylinder head design). A larger 302 build(low geared car with a big cam/heads or a stroker) would benefit from using the RPM/RPM Air Gap.

As far as how the Stealth vs. the RPM would fare, I've been curious about that myself. Just looking at design it would seem the Stealth would favor a lower rpm range and the RPM would favor power up top, since the Stealth appears to have a lower profile design, and the RPM(especially the Air Gap, which is actually a bit bigger than the RPM) would favor the higher rpm range.