On my RVís, Vy and best glide was very nearly the same: 80-85 KIAS, depending on GW & air density. This should be approximately your best lift/drag speed which of course varies with density altitude. If you have an AOA, you can program this, but a target indicated airspeed is usually close enough.
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015