You won't get a huge ammount of extra power out of just changing the carb. It would be best to fit performace manifolds (both inlet and exhaust) in addition because the stocks tend to strangle the engine. I polished the internal surfaces of my stock manifolds and it definately helps, it didn't give it any extra power im sure but it sharpened the reponse a little and reduced the growling considerably. You should consider converting back from electronic carb to the origional type and manifolds, that way you will have more control over your mixture and such instead of making do with computer dictated values.
I think the easiest thing to do to start with is just simply lighten up your car, less weight is always better. (Y)
