How do I know like if my wheels would clear a BBK? I'm not talking about the Z32 BBK, because I had them already before and even though I never tried, my mechanic measured it up and said it would not fit. I'm talking about BBK's like AP Racing, Wilwood etc..

 

Size of the rotors/caliper and the offset of your currect wheels. That's my best guess

 

Stillen has the cutout templates for AP and maybe Brembo kits so you can check spoke clearance...