I bet the RPM will make the same bottom end and top end as the Stealth. Some single plane intakes will make the same bottom end as an RPM. A lot has to do with your engine combo. The 1,500 to 6,500 is just a loose guidline.
I'll take that bet lucky.
The Stealth is better from idle thru 6,500.
The other thing is the cam specs on the rpm range to make power early. Some singles may make the same power as a RPM intake but not off idle. I would rather hit it from idle than come off at 1500 rpm from a stop light. All in combination of the complete car is a must not just motor.
None of these are close to off idle responce.
Performer RPM™ Manifolds (1500 to 6500 rpm)
Torker II® Manifolds (2500 to 6500 rpm)
Victor™ Series Manifolds (3500 to 8500+ rpm)
I would preffer a Holly Contender to any of the above intakes.
Idle to 7,200 rpm with the same air flow as a single and better responce thru the rpm range, gasket porting will bring up the rpm range up around to 7,700 rpm and a spacer plate can even help more if needed in tuning for that application.
My .002 cents worth and .5 bet.
Luv the smell of NITRO in the morning.