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brains
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I m going to ask this question in reference to chevy motors but in fact Im working with a 351w stroked to a 408.

If we have an intake manifold made for a 350chevy and has an advertised rpm range of 3500 to 7500, how much would the rpm range drop putting this intake on a 400ci chevy? Would it be safe to say the rpm range would goto 3000 - 7000 or even 2500- 6500, any ideas on this? I know its hard to answer exactly, im just looking for some ballpark numbers...

Ben
 

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"RPM range" as you suggest isn't a firm spec., just a reference to help pick a manifold that will likely perform well on a given engine. The RPM rating on an intake manifold is more dependent on whether it is a dual-plane or single-plane type and on the length of the individual runners than on the gas velocity in the runners. In fact, as long as the velocity is not so extremely high that friction pressure losses begin to restrict flow, runner diameter is not an important factor at all. My guess is that the manifold will perform in the same RPM range for the modestly larger engine, maybe not reaching the very upper number due to flow losses, but I even doubt that.
 

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i have a 350 bored 60 over and a 406 and swap intakes.the 400 would simply pull the power out sooner.when the 350 hits its power in the 55-6500 range,while the 400 is hitting its power 45-5500 range.the intake would work for both.are talking about a torker or something?
 
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