SketchyZed

Okay this is very dumb to ask but a dual plane intake manifolds have the rpm range idle-5500 some 6k but what if you have a cam that is 2500-6500 or similar?

I have http://www.jegs.com/i/JEGS-Performan...13000/10002/-1 is that really my max rpm is the rpm dictated by your intake or cam?

NoEmissions84TA

iTrader: (1)

Small Block Chevy 265-283-302-327-350-400

Jegs forgot 262, 267, 305, 307.

There is no simple answer to this question, but to give you one - it depends on the combination of ALL of your parts and the entire driveline combo and the car itself.
Notice what I copied above from your intake manifold. Although that manifold will physically bolt onto all of those engines listed, each combination is different, and thus will run differently. Some will rev higher, some make more HP, and some more TQ.
Matching your combination of components carefully so that they complement each other will yield the best results.

sofakingdom

iTrader: (1)

Good place to start is:

Just exactly what does that RPM "rating" mean?

Does it mean that power is guaranteed to be constant at all RPMs within that range? Does it mean that torque will be within 10% over the entire range? 25%? 50% Does it mean that ANY power/torque AT ALL will be produced? Does it mean that the matter will meet the anti-matter and the entire known universe will suck itself into an infinitesimally small black hole if the 5500 RPM intake is operated at 5501 RPM? Does a 2500 - 6000 RPM cam rating mean that your idle speed has to be 2500 RPM? REALLY?

Just exactly what does it mean?

Well, mostly it's ad-copy monkey-spank. But maybe to some extent, it probably means that if you want the motor to run at its maximum potential somewhere within that range, then that part might be appropriate. And then, if that's the intent for the motor, then all of the parts you choose (heads, intake, cam, pistons, crank, exhaust, ...) should be consistent with that goal. No one part will "compensate" for a poor choice or a mismatch in some other part. They all need to work together toward the SAME goal.

Don't try to read any more into it than that.

So, to just make up a scenario out of thin air, a cam "rated" for 3500 - 7500 RPM is probably a YUUUUUJJJJJE mismatch for an intake "rated" for idle - 5500. In that example, about the time the cam got up to the point that it starts doing what it does, the intake starts choking it off. You get the WORST of both worlds: a cam that gives no bottom end whatsoever, and an intake that guarantees no top end whatsoever. You get beat by Kia minivans.

In one of your other threads you posted about using a Comp XR276. That cam, and that intake, would go reasonably well together along with similarly intended other parts, if that's the nugget of info you're trying to get at.

SketchyZed

oh okay just wondering didn't know if i had a bad combo or not, i don't plan on keeping this 355 forever i don't even know if that is a 292 cam in my motor now but i need it for the time being so i can work on my l98 and turn it into a 383

cardo0

Intake manifolds are relatively cheap and you will find plenty on the used market if you need one just to try. But using parts that compliment each other is the way you build power and make performance. For a big cammed 355 a single plane intake with modest sized runners make sense. Something like a Edlebrock Torquer II could be the ticket though I'm sure Holley has something to.

But using the performance built dual plane for Jegs won't hurt the motor but leave some power at the top RPM or high RPM power will drop off several hundred RPM sooner. So you need to shift sooner and may lose more races but that doesn't mean it won't be fun to drive or difficult to drive. Might even drive better at low RPM.

What I'm saying is you need to drive it enough to choose. And maybe try a few different intakes to.