Intake Port Tumble

OOTB, the RPM has larger port openings than the Stealth. So OOTB the RPM flows more air. On my bench, the RPM's average flow is 243cfm, the Stealth is 224cfm. But the Stealth has larger runners than the RPM. Once you open the port openings to the same size as the RPM, the average flow from the Stealth shoots up to 275cfm.

And the Stealth fits better with stock heads than the RPM. If you put a Stealth intake on an engine with RPM HEADS, there is a gap between intake and head because the intake is a bit narrower than the RPM. With stock heads, the RPM intake generally rides high, the Stealth rides lower and fits better.

With RPM Intake and RPM heads, everything fits good. Stealth on an RPM Head, not so much.

Just my 2 cents, been there, done that with these intakes