its 60 to the back not front. They're not that weak if maintained properly i.e not launched at 6000revs, transfer box oil changed regularly and not towed on 2 wheels.
I wouldn't like to say the max it can take, there was a 4x4 turbo running 300bhp on rs2000-16v forum at one point without trouble. The transfer box was uprated thought to pump the oil round better though.