I am selling a spare set of 530cc STI side-feed injectors. They are nearly brand new and from a 2005 STI.
380 obo
They fit perfectly into sr20 stock rail. You do need to make little modification to your stock wire plugs to make them fit into those injectors. I run a set of those injectors on my own 240sx.
I can also chip your ECU(S13 only) to run those injectors with your stock and Z32 MAF for an extra ($150).
If you are interested please let me know.
BTW, if you have an adjustable fuel regulator, you can easily run them as 550cc injectors.