r3dster, for 4g13p... there's plenty of performance carb can be put into... ranging from weber dcoe, dcnf, dgv n etc...... or u can try mikuni or solex carb... well... u dont need much mod after installing a performance carb... but if u want to maximize the power of the carb... u might need few mod like high degree cam, fuel pump, polished head n etc...
hope i help.... cheers
hope i help.... cheers