To replace a hard drive or not

I am reloading windows on a Toshiba laptop for a co-worker. About three years old, 80GB SATA drive.

System was going BSOD on boot, and there were some bad sectors on the hard drive. So I ran checkdisk, which fixed the bad sectors, made a full backup, and reformatted the drive.

Should I swap the drive to be safe?

I plan to run the full (Hitachi) diags on the drive and read the SMART data to see how healthy it is.

Any recommended utilities for doing a thorough stress-test of the hard drive to gain some confidence that it’s not on it’s deathbed?