leagacy parts interchange.

Ok the title is just as I wanted.. I have searched and searched for a list of any and all parts interchanges... I searched for hours... Normally I would continue searching until I was happy with my findings... But I have found almost nothing.. Other than yes you can swap most ej series with most ej serieses most work would be the cross member swap...

But I have found nothing....
Any good sites for parts (performance)
Such as headers, exhaust, intakes, The more the better.. But I have found nothing for my 96 legacy other than "alot of impreza parts will interchange"
well like what? Spark plugs.. well there are 4 so that may be alot of parts......

Anyhelp would be appreciated.....

Also other than performance mods (header intake turbo's etc) also what about the e\xterior.....



Thanking any and all responces in advance