The v8/v9/v10 sti (JDM) all uses the twin scroll vf37 turbo except for the aussie spec cars (aka nz new) which uses a single scroll turbo on both ej207 and ej257 engine
the 6 speed gearbox mostly stayed the same except, with the same final drive ratio on the JDM spec cars except for the fact the v10 had a drop gear in the transfer, so rear diff changed
they all had the brembo brakes, and r180 diff
the v8 had a 5x100 stud pattern which changed to a 5x114.3 with the v9 and v10
visually the v9 looked like the v8 except for the spats on the rear 1/4
mostly the interior stayed the same, as did the body shell. the v9 and v10 had alloy rear lateral arms. some v8 models had the darkened dashcluster like the v9 and v10