I'm changing out my carburator and manifold on my 74 F250 4x4. I have a fresh 1968 460 engine sitting in the engine compartment with the stock man/carb. The engine was rebuilt with stock pistons to keep the already high compression of the engine down to about 9.2:1, and it has a little larger cam, like an RV cam.

I'm going to put an Edlebrock 750cfm carb on her and was looking for an appropriate manifold. Looking at the performer and the performer RPM as the two that I have nailed it down to. The performer is recommended for idle to 5500 rpm and the performer RPM is recommended for 1500 to 6500. I'm thinking ther performer might be the best one for a truck.

There's also the Weiand Stealth with hp between idle and 6500 that I just noticed??? Hmmm.

Any input please??? I'm looking for the most appropriate carb/mani set up for a heavy duty 4x4 truck but also want to get glued to the back of my seat when I stab the accellerator on the street.

Thanks guys,

 

i wouldnt waste the $$ on just a performer...its basically a stock intake made out of aluminum...minimal performace gain, mostly just weight savings...go with the weilend stealth or performer rpm....i run the rpm but wish i had went with the stealth, they are both dual-plane intakes made for bottom end power...i think the stealth makes a little btter torque. I cant remember, i found some data awhile back where somone dyno tested all the differnt intakes on a 460 ford and posted the #'s on the internet

for a stock motor 750 is overcarbing it....you would be happier with a 600 or 650...better low end throttle response and more efficient

 

i would use the weiand intake with a 750 edelbrock. a 750 is a good size to go with a 460. i am running a 750 and a high rize weiand on my 351m and had to change out the jets for bigger ones when i tuned it.

 

good lord, that poor 351 sounds like its waaaay overcarbed

unless you have it seriously built to run 6500+ rpms

 

it has 30 over bore,shaved heads, a energizer cam with 539 kift 278 duration, hedmen fenderwell headers, weiand highrise intake, 2500 stall converter bolted to the back of it. i put the 750 on it and through time triles i had figured out i needed to richen the carb up on the primaries and secondaries. it all resides in a 78 f-150 with 35 inch tires 8 inch lift and 5.13 gears.

 

Thanks guys!

 

The single plane torquer although a good intake is ill suited for use in a truck where torque is the name of the game. The single plane intake will trade torque downstairs for HP on the top end and if you do not have the cam to utilise it will make less overall average torque and HP than the performer. This is especially true if you use a 2" 4 hole spacer to add needed plenum volume to the performer.

Intake manifolds like all other components on a performance 460 should be chosen based on the choice of ancilliary components used for the build. A torque biased combo will be best suited when an intake with small runner cross section and high velocity is chosen.

The best intake by far for torque under 2.5K is the stock iron ford intake. Its problem is lack of plenum volume and the size of the holes on the carb pad.

Next in line is the performer intake which gives up a tick of torque below 2500 RPM but will add some 25 HP over the iron intake (stock pass car) and with a good spacer will add some 15 to 20 more HP for a total of some 40 HP. The performer has two different runner cross sections for a broader torque curve to some 4K. I use this intake on builds that utilise less than 220 degrees of duration @ .050" lift. 450 HP top side limit is about average.

Next in line is the performer RPM which starts to shine when you use more cam duration. I use it when duration @ .050" lift is above 220 @ .050" lift. It has larger runner cross section and will give up some low end torque and response below 3K vs the performer especially when the performer is paired with a spacer. I use it from 450 to 550 HP

The stealth is a higher RPM intake and I compare it with the RPM airgap which has smaller runner cross section than the stealth but larger than the rpm and performer. The airgap is by design meant to be port match per intended use. On a bench the airgap will out flow both stealth intakes due to its better runner velocity and larger plenum area. I use these higher RPM intake on builds that utilise a cam of 226 degrees duration @ .050" lift and above. I have yet to test the airgap against the stealth but my gut and experience along with some anecdotal track time evidence show it to be as good if not better than either stealth intake. Testing will bear this out and have the final say over my educated guestimate. If you do not have enough cam to utilise the higher RPM capabilities of the larger dual planes the trade off in low and mid range torque will not be off set at the higher RPM ranges these intakes are designed for. I use these from 550 to 650 HP which is about their limit.

With regard to testing all of the intakes on a combo with a 216 @ .050" lift cam I feel the results are suspect at best. You can not test a single plane intake such as the victor on a combo like this and expect it to be anything other than a rutting pig. The results show nothing more than which intake is best for a given combo but not overall. We have debated this ranking of intakes on the network 54 BBF forum and the statements I make here are more in line with consensus there.

The statement that a dual plane dual 4 barrel BT intake makes more HP is ludicrous at best. A victor is 40 to 50 HP better than ANY dual plane intake ever thought of being when a combo has the cam to utilise the RPM band the victor was designed for period.

My experience and the experiences of many engine builders I trust implicitly (from our BBF network 54 forum) bear out the fact that the stealth intake is a very good HP intake but it is softer on torque below 3 to 3.5K vs the stock intake and the performer by some 20 pound feet. From a driveability stand point it offers less runner velocity and response because its runner cross section is huge compared to any other intake mentioned here including the victor. For accelerating with a loaded trailer from a stand still I would bet the performer/spacer combo would outpace the stealth to the legal speed limit.

I steered my client to the performer because of the displacement and intended use. The fact that the performer pulled like a SOB well past the cams usuable rpm range bears this out in my mind. Hell the intake pulled well past the point of valve float onset and pulled like a freight train at that.

I am not convinced that a stealth would be a better overall intake for a mild combo like richards (or kevins) (both utilise the same cam by the way). I had both the stealth and airgap in stock at the time richards build was going together and felt that the performer was a better choice. Factors such as C/R, cylinderhead flow, cam specs and header design were part of my decision as well as fuel economy and I stand by it. Remember high runner velocity makes for great average torque and HP not fat flow numbers with big runner cross section. How a combo feels on the road in my butt dyno is a far greater indicater of client satisfaction than any dyno results believable or not.

By participating in engine masters I learned that average torque and HP with in a given RPM band are more important on a street biased combo than peak numbers be they torque or HP. Average numbers accelerate a combo far better than a peaky combo with poor overall performance across the lower end of the RPM window of operation. The heavier the vehicle the more important this is.

For kevins situation spending another $200.00 USD to add mabey 20 HP and give up 20 pound feet seems a waste of money when the performer and a spacer will do him just fine.


Scott J. / RHP
http://reincarnation-automotive.com
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