220 mhz antenna question

I've been considering purchasing a 220 MHz radio however the selection of antennas is slim to none. In my case I'd not rather use a 1/4 wave NMO mount antenna unless I have to. My question is: I have a Larsen KG450UDK on glass antenna that I'm not using. Would it work if a longer whip was installed tuned to the new band and what would be the correct length? Currently this antenna has a 12 inch whip which is about 3 inches shorter than a 1/4 wave 220 antenna.



Thanks for any input.