Still trying to figure out which one works best, either reprograming the OEM computer or replace with performance chip? I don't want to blow the engine, just get moooore power out of what I've got, 2003 350Z Touring, 6sp. Any thoughts, ideas??

 

There is not such thing as replacing the chip for the VQ35. You have to flash the ECU either Technosquare or Altered Atmosphere can do this. Cost is like $600.

 

+1 , but without mods you will waste your $$ unless you plan on never moding then go for it the ECU flash. You might gain something with no mods??