High port flow gives great performance now, and more later when additional upgrades are doneHeads are fully assembled with springs and valvesCompression ratios vary depending on cylinder heads...
Unique S&S design dual-spring kit reduces the risk of valve floatFor valve lift to .585" with 1.800"/130 lb. installed height, 325 lb. at max liftIncludes springs, top and bottom collars, keeper...