I bought some civic sedan dx (not ex) calipers for my DX hatchback hubs and they bolt fine but the caliper bracket hits the outer side of the disk by a little bit. I am not sure if its the disk that Its not pushed all the way in since its all rusted out.

I will buy some new disks and pads to see from there.

but I though that all DX and SI calipers interchanged? has any body had a problem like this before?