Nissan have two filters u can use for a r34..
Small one made in japan, and a larger one that is made in thiland.
Now when i go and get filters for my mates Gtir they give me the small one, yet when i get one for a 1.6l N15 pulsar its the large one, so i dont see a problem using a SR20 filter. Best to check the car your self.
The reason they did this is due to space. Some ppl like the smaller filter, i myself like the larger filter.
When i got my car from the dealer i know it had just had a oil change... had a ryco filter on it.. and i know they dont have them in japan.. i went straight to nissan and got the filter, and i compared it to the one that was on the car. Just look to make sure the seals are in the same spot , not much to it realy!