Somebody would have to explain to me how valve weight affects spring pressure. It's the lobe lift that dictates spring pressure. At least that's how I see it......maybe I'm misunderstooken.Like roller cam or solid flat tappet or what? I guess what I would consider is the lighter the valve train is, can I get away with less valve spring pressure. How much I could gain in power (lower et) and greater engine longevity (more runs per valve job).