gearbox question

dear,

I own a motor vehicle from 1998 Seat ibiza 1.4 16v 74kw. The vehicle's original transmission has failed and I need to replace it. The stamp was marked 085301103H G5. I found a correct gearbox with tags 085301103H G4. My question is, is there a difference between the two transmissions? If there is, can I move the gear and idler harness from the 085301103H G4 transmission to the 085301103H G5 housing, keeping the differential from the original 085301103H G5 transmission.

With respect!