I'm not sure if it is common knowledge as I've heard quite a few times requests for P38 HD CV's and wondered why D2 CV's wont fit. Anyway, if it is not common knowledge, there are HD CV's available now.

These are made by RCV Performance products. I understand they make the world renowned Longfield CV's and I understood they made the Ashcroft ones too (might be wrong).

Anyway, if your P38a needs a super tough CV then these will be it. The inner axle is 30 spline at the CV, so I'm guessing they have leaned quite heavily on their Toyota designs when making these.

You wont break them.

Ultimate CV Axle Set for Range Rover P38 ('94-'02)