Yes, a thinner o-ring will be required if fitting to a std fuel rail. All the Jap injectors are made by Nippon Denso so brand name eg, SARD, Biltz etc is irrevalent. I believe a batch of SARD (Nippon Denso) injectors need to be filed down, this has now been rectified so some old stock will need modification. Please don't start a brand war as people who do don't know what they are on about. HKS, Blitz, SARD, Nismo etc are all from the same manufacturing plant.