Hi mate, the drive shafts are strong, the only problem i have found is that the pins wear quite fast, for the front i can get a steel drive shaft thats wears better. The only mod that i had to do was grind a small bit off of the the rear engine mount ear as it just rubs the engine, and a small bit out of the the chassis braces but it didnt weaken them, only because the drive shafts are a bit thicker.

Cheers
Scott