Parts needed for jumpy belts 1982 GMC Jimny

[Reel Easy]

Do I need to replace both the harmonic balancer and install a dampened crank pulley or just the pulley? Can anyone give me part numbers?
Thanks
Randy

[DmaxMaverick]

Welcome aboard!

Just the crank pulley, but it's always a good time to give the balancer a second (or third) look. The part numbers are very specific to application, so you'll have to look it up with a supplier according to VIN, or hit/miss comparison. Also check all the accessories for true running. Good luck!

Or, if you're going to keep it a while, look into a serpentine belt upgrade. A bit costly up front, but almost all the headaches of V-belts disappear.