Stock driveshaft is listed as 10.5kg on realoem but not sure how accurate that is.
I'm not as concerned about the weight, but about strength. I've already twisted my driveshaft twice in ways that it wasn't designed to (stupid diff bolts like to break on my car for some reason). Honestly surprised it hasn't broken yet.
Sometimes it makes funny noises and I'm crossing my fingers it doesn't blow up the next time I do a pull at 30+ psi LOL