256mm conversion PLEASE HELP...

[Alexiskayak_7]

Please help me...
I bought cariers and calipers from a 16v astra, discs from a mk2 golf gti, an i see that the pads does not fit axatly (there is a gap that the pad does not get in touch with the disc, so i have small braking area....)
Please tell me what pads do i use?
Any pictures will help...
Thank you very much...