I have a set on my SS 383 Dart. One of the roll pins slid out and beat up the keepers and retainer a bit on its way to flying out... this happened with only a couple, maybe three hours on them and the brand new engine.... I replaced the one rocker, a spring and some other small parts just in case. All has been happily racing for many many hours since without a hiccup. I'd recommend them, but I'd like to solve my own mystery as well, if you know what I mean. Maybe a quick test of the pins before use to make sure there's some tension on the pin spline??
Forgot to add... we threw out their shims and set the heads up with a B3 Racing custom shim set and custom length pushrods by Smith Brothers. Excellent way to go, IMO.