The 2003-up (Gen III) 5.7L/6.1L Hemi features aluminum heads with much smaller 84.9cc combustion chambers and dual spark plugs. Volume reduction avoids the need for hefty piston domes, yet still gives 9.6:1 compression with the modest dome shown here. The included valve angle is also smaller at 34.5 degrees to reduce overall engine width, yet bore shrouding is minimal. Traditional double rocker shafts are employed, but raised cam location in the block allows shorter, lighter pushrods and rocker arms. If this isn't a Hemi, we'll eat our hats.