500 has PW127-F
600 has PW127-M
Not the same engines, check their web site.
The latest -500 are generally fitted with PW127M in the new version, the orginal 1997 onwards variants are fitted with the PW127F powerplants, the difference being the si blades over five blades.
I have heard VA will initially get -500 until -600 are available and then the -500 will be returned.