Can you tell us what frequency they are on? If they are on 72 mhz, and the sticker is a little gold trapezoid with AMA (in black IIRC) on them, then te Txs were narrow banded likely by an aftermarket source such as Radio South. If they are on 27 mhz, thre was never a need to narrow band as this frequency retains the original channel spacing.

I'd be equally concerned with any receivers you may have. If they are not narrow band as well, they could be influenced by Txs on adjacent channels.

John C