Yep...it's a separate radio. so in my 60 I have the ft-8900 for my 'cockpit' radio and the 2500 is mounted in the back with the APRS junk plugged into it. I have the mic stored as well, just in case my other radio craps out.
At one point those 350's were a smokin' deal. I wish I picked one up. I do, on occaision get interference (zzzt...zzzzt....zzzzt) but the reality is my Fridge is creating so much I don't notice any APRS noise anymore.