I have reused them before...when I torqued them I just added an extra 10lbs of torque to them. It is recommended to get new ones, so you might as well get ARP head studs...can reuse them many times and their about same price as stock bolts...I believe there slightly cheaper honestly. I personally have reused the same stock bolts 3 times and was running 14lbs boost and never popped a headgasket...I highly suggest against doing that though. ARP is definitely the way to go.