Here's a shot of the new Manley titanium retainer and Chevy Gen III (LS1-type) valvespring in place on the Hemi. Notice how the rocker arm-to-retainer contact problem is totally solved. Though the lower retainer placement does alter valvespring installed height and increases open and closed spring pressure, the difference is under 20 pounds. Because the custom valves retain the OE valve length, the Hemi's excellent rocker arm geometry is not affected. Because any 1.290-inch-diameter Chevy Gen III valvespring now fits the Hemi (right out of the box), you have a nearly unlimited selection to choose from, plus unquestioned spring durability.