Do I need a hardened intermediate shaft for a HV oil pump?

...yes...you need hardened. also remember that some of the new bushing might need to be "reamed" to size. usually if the old bushing is good, I would reuse it if it is in good shape. Don't know where you would find the reamer for the bushing. Anyone know...? In any case, check the fitment of the shaft to the bushing real good...