Narrow band compliance and 2.5 kc steps are 2 different issues. You can have an older Astro series radio that IS compliant, that may not do the 2.5 kc steps. Not everybody has to change frequency with narrow banding, only SOME new allocations are using the 2.5 kc step channels. Again run the number in the FCC database, it will tell all.
Having to narrow band some 2000 plus radios, kinda makes me an expert at this. Unfortunately.LOL
A little bit of what I have to deal with. Vertex FTL-2011, some old Yaesu, Repco 10-8, Repco RPX crystal, Repco RPX synth, Harmon RC-4, Aerotron Alpha and Omega, Harmon Trackstar, Trackstar II, Motorola Syntor, Mitrek,Spectra Clean Cab, Spectra Cab car AAR. GE MPA, MRK II, Panthers, Orions, M7100,GE MASTR III bases and voters. The newer stuff that just needs reprogramming not replacement, Motorola CDM-1250, HT1550, HT1250,EX600,EX500.Icoms F-3161's and FR5000 and 6000. So anybody that has a large fleet or even a small one, believe me I feel your pain.