I've got a Tiger2 and it's the heaviest 46size I've built in about 8-9 ARFs in the last year. The T2's fuselage is all plywood. I believe there isn't a bit of balsa in it at all. When I opened the box and saw that the fuse was ply all the way back, I knew I'd need to push everything forward. I still needed to use a larger battery. And the airplane is almost 6 pounds. It flies great, in spite of it's "gross" weight (pun intended). Your T60 just might be the same, but that's not what you asked is it.

If you've been around here much, you've probably seen the posts that talk about balancing a low wing airplane. They suggest you turn the airplane upside down in order to easily accomplish the job. They ought to suggest that with most low wings, it's about the only way to even do it.

Upside down is just as accurate. It might actually be more accurate with some planes that have long wingspans and deep fuselages. It's surpising how often those really tippy ones (when balanced upright) wind up with too much weight to balance. Even after they're "balanced" they're hard to recheck. So who knows for sure.

I've not seen a T60 "in person" so don't have a clue but, if the fuselage does not have lightening holes toward the tail...... Putting lightening holes into a flat sided airplane, even one that's already covered, is a dead simple job that takes no effort to do well. All you need is covering that matches. But adding lightness is a last resort.

After you've moved what can be moved and added what is needed, fly it. If you don't like the way it flies, THEN do the extra effort.