Make sure the counterweights are lubed, there is a tool to lube the outer bearing in the hub, it is like a clamp with grease zerks. Check for play at the blades in twist. If in flight you notice any unusual vibrations, get on the ground and have the counterweight bolts replaced. 3 of the 6s I took care of suffered bolt failures, 2 on take off, one had given some warning, the other did not, the other had a vibration and when the prop went to the shop and the bolts pulled, one was found to be cracked. There is no way to inspect the bolts except by removing them, but they cannot be reinstalled as they are installed then drilled.
My T-6 show and tell collection
