I have bashed a couple of 4*60s and they fly great. There are 2 things you don't want to do.

First, don't increase the wing span. The best thing is to remove 1 rib from each side. The plane will roll better and you won't notice any change in landing. If you want to round off the wing tips, as I did, cut off 2 ribs, then add big, rounded tips back on.

Second, don't reduce the size of the tail, either vertical or horizontal. Both are fairly small. You can easily add an extra inch of rudder chord and a half inch of elevator chord. I added to the length on mine, too.