front has two different part nos , one for left and one for right, they supposed to be directional, i think i have d actual nos somewhere. also i might have some new ones lying around.
bro u are overthinking all this , i believe u should get on to an experienced legacy guru and u will be able to get what u need without breaking the bank.
meth adds a certain margin of safety once tuned properly. however on a legacy i went thro all the stages with mines and ended up removing it as i found it to be a hassle on a daily driven car. i retuned and got very similar results without meth compared to my nos with meth.
Im the owner of the legacy, the car was dynoed and it made 220-230 whp , as it was run with in bago dex. it is capable of making more power but was run on low boost!!!!! as only low boost was set up on d new controller which was put in two days before bago dex, HIGH BOOST WAS NOT TUNED AS YET!!!!!!!...
si drive come with a vf44 turbo where az non si drive comes with vf38 which is smaller. also aside from different throttle inputs it has two mappings so the sport is alot more aggressive than the non si drive .
ragnarok the legacy ej20x comes with avcs both on intake n exhaust cams and duration is different ie a exhaust cam cannot be used for an intake one etc.