THe biggest strings that I ever put on a guitar were 12-52's.
I had a friend who was a guitar tech at a local music store, and he had a Yngwie Malmsteen strat.
Anyway, he put a custom set of 14-70's on there cause the scalloped neck let him bend them.
But, he had to take them off cause the neck almost snapped.
When attempting the impossible, you achieve the best possible