im still in the process of building my turbo kit on my 06 cobalt 2.2. i noticed my fuel system is a duty cycle (non return) fuel system so my questions are what are you guys using for fuel pumps? will a walbro 255 pump fit in the stock pumps place? how much modification is involved? i want to keep the stock returnless fuel system. trifecta said they can tune with it to my needs so im going to leave it.