I have a 1990 300zx 2+0. These injectors fit my fuel rail no problem. You do need to press them in hard and twist though. Here's the only issue I have with the adaptor kit. For cylinder 1 injector, you will need to grind a bit of the plenum away for the injector connector to fit onto the actual injector connection. It's a little annoying to have to do, but the part of the plenum isn't crucial so don't worry. The website should state this, seems kind important. Also, please send me a sticker plz.