Well you said that you put the coilovers into the hubs and had to make a spacer so they didnt move about. Mk3.5 fiestas having larger diameter shocks and hubs would lead me to believe thats what you are running and im assuming you done your homework and made sure the GAZ coilies came out of a frst. So if the coilies are 100% correct and they rattled inside the hubs, then your initial set up was from a mk3.5.

Regarding wheel spacers, i cant help. My frst was running fk coilies and also 5mm spacers and mondeo mk1 studs, and my 8 x 16" oz mags didnt buff at all.