Hi,
yes it's possible, here are some tips:
1)
https://www.gavick.com/documentation/jo ... f-the-menu2) Class'es used for menu
a)
#aside-menu li - if you have aside menu only
b)
#gkHeaderNav .gkMainMenu .gkmenu > li - if you have classic menu
now you can use one of those class in Fonts tab in template settings to choose other font