I reuse head bolts unless they have pitting or heavy rust. I replace rod bolts on E6/E7/Etech engines, never reuse, that's our company policy. Just a note, main bearings are the same on #2,3,5&6. #1 looks the same but it is not, the tang is slightly offset. If you mix that bearing then you loose all crank thrust. Seen many tech's scratch their heads trying to figure out why there is no crank thrust after replacing main bearings. Good luck