Did you check the bolt pattern against the PT6 manual before you mounted it? I learned the hard way that those universal adapters are rarely universal, especially for turbine engines. The CNC tolerances on the cheap ones are just too sloppy for anything precision. A quarter inch is a massive gap, that's practically a different engine bolt pattern altogether. I'd be worried about how the whole stand is built if they messed up something that basic. Better to spend the extra cash on a adapter made for the specific engine model.