I've worked on two that the upper stud broke .. The first was my own (kevlar belt). ran compression 170 all 6 .. just replaced stud and I use it as a dd run 15 psi boost everytime I drive it. The second one was a engine I got for doing a Jspec install... The person who owned it ran the bearings out of the pulleys .. Two weeks of squealing and he didn't have a clue... bent valves.. Good Luck ... I personally installed my own. The trick is to install the belt with the proper tension gap on the tensioner..