I wanted to do the same, but from what I've gathererd from this thread; this plane with it's long nose has a tendency to nose over already. That fact combined with the fact that gas engines which are known for being notoriously heavier than nitro engine (not to mention the batteries for the electronic ignition) will be an awful lot of weight for a plane which is already heavy for it's size, leads me to believe this is where all the hesitancy comes into play.
I suspect, it would work fine as my MVVS 26CC is essentially the same as the Evo 26cc, but others convinced me to keep the wing loading light.
I'd encourage anyone to do it, and would prefer if someone did it before me.