Mikesluv

I have a 2007 chevy 4.3 and I'm putting a 02 5.3 into it and I trying to figure out what I need to do about the fuel system if I can use the factory pump or if I need to change it out. Thanks in advance

jetech

Yes you can use the factory fuel pump as long as you are not looking at forced induction. Both factory setups use the same pump

strutaeng

Did the 4.3 retain return-style fuel system into the GMT 900? Or is this the GMT800 classic?

I did a 99 Silverado ecsb 2wd 4.3 to 5.3/4L80e swap. It's a great combination. Just source an engine wiring harnesses from a 03+ as the 99-02 are different and not compatible with the later ones. The fuel pumps are the same. I think in 2004 or so is when they switched to return less. I'm not sure on the V6.

jetech

I think 2006 there was a change over at some point for returnless fuel system. Some 2006 4.3's had a fuel pressure regulator and others had a fuel pressure damper. The regulator being used in the return style system