do you mean you have a nasty k&n bolt on filter? if so yuou want the complete std airbox from a MK2 1.3. The GTI airbox sits on the inner wing, you have no way of connecting it to the carb!
However, some SEAT SPI engines or perhaps MK3 Polo GT have a setup that may work, they use a carb style connection on the SPI/throttle body with a pipe that runs to a GTI style airbox on the chassis leg. MK3 Golf SPI engines have a different airbox, which might be adapted to fit bot the piping to the engine may be usefull.
Problem is any MK2 GTI airbox you cet wont work with this as if its a k-jet it'll have the metering head, if its a digifant it'll have an AFM, neither of which will help your carb suck in air easily. What you want is the SPI airbox from a SEAT SPI box or one from a MK2/SEAT diesel to go with it.
But at the end of the day non of the above is going to gain you anything over a standard 1.3 pancake filter housing! Apart from it may be easier to source!