RE: Installing Lipo in Old SuperCub...Need Advice
You should find out what the CG is and balance accordingly.
I dont know the plane in question...but someone already stated that a 1350 zippy (3cell) would fit the original battery compartment. A 2200 is going to be double that size/weight. So I would say you are definitely tail heavy IF the battery compartment is on the CG. I dont know if I would add more weight or not. Wont hurt to try but that is going to be a lot of weight.
Probably best thing to do is go with a smaller battery like a 1350 or somewhere around that. I fly my mini ultra stick with a 2200 and 450 BL motor and I had to push the battery pretty far back in the fuse to get CG right. I cant imagine you could remove enough material from your cub fuse to get it to balance without adding weight or sacrificing fuse strength.
Go with a smaller mah battery, like the 1350 or 1550 someone posted about above.