joe_mirage,
Lift controls the size of the opening, duration controls how long. Flow rate depends on pressure difference between the engine head and block... which will tell you that there is an 'optimum' opening size... thus the reason for having different cam-lifts for diff engine models or specs (although same durations).
Btw, regrinded cams do have additional lifts, but in a different way. Rather than having a high lift, instead, they use, erm, forgot whut u call it, to make the valves longer in a way, thus making the cams act as though they have higher lifts. So instead of bringing the cam loves to the valves, they're bringing the valves to the camlobes.
Not sure if u can understand this explanation lar... if come out TT and I have a paper + pen, I can draw for u, use some hand motion and all, then u can better understand. hahaha... a bit difficult explaining thru words only. But since this way is not very proper, thats the reason why i don't like the idea of regrinded cams. A lot of people patah their regrinded cams before also, usually during races ler. The cams can't sustain too much torture, because when u regrind them, you make them weaker than they are (coz' u shave off material, make it thinner).
hullyeh,
wuish.... welcum to the gang! =)
u forgot to mention urs is in a wira/satria/putra/iswara/saga/lancer/others...?
gobbi,
You need quite a number of things, not just the fuel injection. Wiring will all need to be re-done... and you need an ECU as well. So best u get back all 4G91 stuffs, else it wouldn't be compatible.
very powerfull...! 
