I recently bought a a 02 wrx.  It supposedly has a STI block. Any way to identify if it truly is a STI?

 

Thanks all!

Between the power steering pump and alternator there should be a stamp. If it says ej20 it is wrx, ej25 would be STi.

There were Sti and regular wrx versions of both the ej20 and ej25.

Find the VIN stamp and run the VIN on google.

Should be either on the top corner above the starter, or on the opposite bottom corner.

 

If there's no VIN its probably a Subaru replacement, although there is supposed to be an EIN on it in place of the VIN, but you would have to get Subaru to run the number to confirm.