You cant change the carby cos there isnt one, CFI stands for Centre-point Fuel Injection, if you take the top of the air filter off you can see the 2 fuel injectors.
You could work up a CFI and get better results than standard but whether or not you can get results just as good as a worked MPFI is a mystery, I was talking to my foreman (who has worked for ford and ran a ford dealership for 3 years and helped design the fuel injection systems on falcons) about changing over to MPFI so I'd have a good base to start on for mods and he said I'd be wasting my time and money cos there isnt much to gain unless you started mucking round with the manifold
The same mods apply to what you'd do to any other engine, depends on how crazy you want to go, alot can be done to the head, LukeyN gained something like 18kw from just a set of extractors, but yeh, the sky is basically the limit
Phat Drift Damaged
Cobalt Blue 1994 EF XR8 5 spd
Fully optioned - Sunroof, cruise, body kit
Stock as a Rock for the moment