There is only 1 mod for the 2500, regarding opening the tx to 140-174 Mhz.
It involves taking off the top of the radio and cutting the short, very
thin green wire atop the board near the low and mid power pots. There is
no extended rx mod, so we're stuck with the stock 140-174 rx. Be careful
with the little plastic plug when reinstalling the top cover. Follow the
manual exactly when replacing the cover. I believe there is also a packet
mod, as explained in the manual, but I haven't done that one. 73/Terry
VE4UC