novarally

I bought a pair of brembo STI8 front brakes and was told they would fit on my 1994 wrx
First attempt the pcd was different on the disc as the brembo disc is 114 and the WRX is 100 so went to Godspeed and had the discs drilled out
Second attempt today disc on great then put caliper on and the d**n thread on the bolts are different
Has anyone come across this before and if so what bolts do I need that is 12mm by what thread 1.25 or 1.5 and also I put the old brakes back on before measureing what length these bolts should be
Any help will be very much appreciated
Thanks