Are the stock 550's top feed peak and hold?

 

I'm slightly confused to what you are asking.... are you asking if its top fed or side fed??? All 3rd gens have side fed injectors from factory.. 550s means usually at 100% duty it will flow 550cc/min. If you want top fed, you would need special rails to use top fed injectors. There are ton of companies that make special rails for 13B's. But usually people prefer to bore out the stock injectors because side fed injectors do better at higher duty than most top fed.