[MiracleMax]

If I think wayback to some articles about comp using the spintron I beleive this was mentioned.

However, in most of the stuff I've seen currently (applying to hydrualic roller lifters mind you) weight seems to be an issue. AFR developed thier hydrarev rev kit for SBCs to help stabilize the valve train at high rpm. Now this may have to do less with the weight of a hyd roller lifter and more to do with harmonics, but it looked like an issue that could be addressed by making a composite body lifter (not meaning ceramic or carbon fiber, but rather using two or more materials to build the lifter).