The prado afaik uses a slightly different turbo, different EGR valve, Bigger intercooler and obviously other software. The map from a prado won't work on a S/C D4D, as the vehicle has a completely different setup with other control units and modules that work in the ECU.
The basic engine is the same, but the rest is different, as it is a completely different vehicle. Also the reason why the Hilux is so low spec on torque is to make them last longer under harsh conditions which a prado will most likely not be subjected to.
I will be honest and say, go for something like a plug and play unit if you want a bit more power.
Also just remeber that the more you have the more you want......
![Twisted Evil :twisted:](./images/smilies/icon_twisted.gif)