Unless this is some heavily modified PT6A-60A then the governed range of the primary governor is 1450 to 1700. The N2 section of these engines spins at about 30,000 RPM and the reduction gear ratio of the -60 engines is 17.6:1. 1700 RPM is the maximum you should see in normal operations.
I have flown and instructed in King Air 350s in the past and have over 25 years of experience in flying and instructing in various models of King Air (90s, 200s, 300s, 1900s.)