[StanJ]

We've used Schubeck's full-composite and ceramic face flat tappets with great success for several years now. The weight savings is particularly advantageous when using aggressive lobe profiles that require larger .875" or .904" tappet face diameters. The only negitive aspect we've ever seen is the fact that -- while the ceramic material used in them is extremely hard and therefore almost impervious to wear, it is also quite brittle compared to a conventional chilled-iron tappet. I'd recommend against trying to incorporate a significant reduction in valvespring pressure...unless you have the time and funds to invest in Spintron testing of your complete valvetrain package. Judging from our experience, if you "vault" these things over the nose of the camshaft lobe...even once... there's a very good chance of it turning to dust when it slams back down.