I bought "Eddy's" for a 5.2L, before the RHS heads were well known. It "looks" like alum. head has a faster burning chamber. Some contend you can run approx. 1 point higher comp. on same octane. This should equate to higher torque/hp. ,somewhere in the rpm. spread ? I needed the reduced weight, to replace a /6 and keep the orig. torsions and better corner burnin. How is the RHS head flow #'s, "out of box", when it's got 4 angle valve job and bowl blend? While we're no longer, out of box, what do the Eddy's flow, with moved int. pushrods? 2cents, Ateam.
