when they first came out the quality control was all over the board. i heard as recent as last year guys were breaking the rockers themselves in half at the adjuster AND the shaft. as for mine, i saw that the machine process itself was complete crap and as stated already, spotty at best. mine about half the rocker arm adjustment screw holes weren't even centered on the rocker (seems that many failed for that very reason). mine also fit really sloppy on the shafts themselves. there was much more, but i fail to remember it all (i try to block out the bad lol). i put mine right back on epay and as i disclosed what i found on them in the ad, i took a bath on them.