Well, owner of the one i've done was a racer, so he was interested in increasing power. It wasn't hard to groove that throttle body, but metal of which it is made is really strong. I didn't re-route idle air pathway.
I can say that after that car I've done Mercedes Vito 1999 2.3 (no compressor but the engine is the same). Before modification it needed 14 liters / 100 km, and after year passed I met it's owner again to see how was going on, and he said, that in winter, when it snowed the car took not more that 11 liters per 100 km.
So I wish you good luck with that car! Everything will be allright