You can play about with the turbo actuators and the fuel compensation but you won't get the kind of muscle offered modern diesel engines which are easily tuned via the diagnostic port. You might also find it can be a bit sooty if you go too far.
What you will find though is that the Isuzu engines are utterly bulletproof
Be careful with the angel eyes though, they're not type approved as an aftermarket fitment - you don't want to invite needless police attention. The same problem exists with aftermarket HID lighting.