Nero,
Which not so strong, G50's are you speaking of? I had a 392W(514FWHP)in my car for a while, and the only problem with the drivetrain(rebuilt, inverted G50-01), was the inability of the stock clutch, to handle the torque(blew the springs right out of it!). The gearbox was pulled apart shortly thereafter, to re-press an output shaft bearing, that wasn't seated properly, when my LSD was installed, and everything inside looked like new.
Believe me when I say, "I have NOT been very easy on this gearbox!"
Since re-pressing the bearing, and installing a more streetable engine (351W/425FWHP),the box has remained tight, solid, and reliable. And NO, I haven't been any easier on the gearbox! It won't chirp the tires, when shifting from 3rd to 4th at 90MPH+ anymore /ubbthreads/images/graemlins/frown.gif, but it's still a load of fun! /ubbthreads/images/graemlins/cool.gif
Bill