Checkout Redbook for the details.

The Patrol GU II Ute basically come in two variants;
The Leaf version (coils front & leaf rear)
Leaf
Towing Braked (kg) 2500

and the Coil
Coil
Towing Braked (kg) 2500

So from what I can gather the GU II Utes were both 2500 kg. The 2006 Wagon however does appear to be rated at 3500 kg.