We cannot over stress the importance of using new genuine factory specified fasteners when rebuilding your motorcycle.
The very structure and strength of the assembly is dependent on this bolt or screw and being perfectly tightened with the correct torque. The old bolt will have stretched and be effectively useless!
Always renew these highly stressed bolts during engine assembly. Use the correct genuine factory fasteners for the best results! Genuine spares are frequently good value and ALWAYS great quality.