Thanks mates....

I did some experiment yesterday with c22 rotor&caliper and 910 strut.
C22 disc/rotor perfect fit to 910 hub. Even the centre bore is same size.
C22 caliper direct bolt to 910 strut.

Only thing need spacer (aluminium?) to align caliper to same line with disc as the c22 caliper bracket thinner than 910.

I have Japan spec b310 as a donor car to my current b310 project. This car comes with 510 / a10 front strut as standard to fit 13" wheel.

earlier I mod the c22 disc and caliper to standard b310(Malaysian spec, 12" rim) strut. But not confident with the engineering job. Terrible ugly welding. Very unprofessional.