given the published flow data I've seen on RHS's and eddies, I'd think they'd be pretty close power wise, maybe 10hp more with the RHS's...but they'd also be 50+ lbs heavier.
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)