5.3L Chevy Motor Swap – Fuel Delivery

I did plenty of research on this…and actually still am researching this topic, but I have made some decisions on how I’m tackling this part of the project.

The first step for me was to take the tank and drop it… luckily I had purchased a poly fuel tank so I never have to worry about rust, I just had to deal with the 4 year old gas that was sitting in the tank, so I emptied it…and took the opportunity to replace all of the hoses that went from the tank to the various hard lines in the back of the Jeep.

I also did quite a bit of research on how much fuel pressure the motor was expecting to receive from the up-stream fuel pump. Apparently the 5.3L Chevy motors require somewhere between 58-65 PSI on the rails… I was able to find several pumps that people were using for this application, but the one that people are recommending, especially on LS1Tech.com forums is the Walbro 255, (255 litres per hour, providing plenty of pressure for the motors injector system).

Also interestingly, my particular 2001 model motor (luckily for me) has the return rail right on the motor as well…so I don’t have to deal with a regulator and pump unit on the Jeep frame…all I have to do is plumb up from the tank on the passengers side into a filter, then from the filter to the pump, and from the pump to the motor supply rail, then from the return rail on the motor down to the return line on the drivers side of the Jeep…  The line from the pump to the motor supply rail is supposed to be a high pressure line (of course) made for Fuel Injection systems…and I am going to try to find braided line, because it will be very close to the motor itself and I just want to be extra cautious with this!  I also found that the line SIZE should be “6 AN”.   and on the fuel rail itself, it’s called a quick-connect 6-AN, and Russell Performance products makes some adapters that take the line size into a quick connect adapter so I can plug it right on the rail without having to use hose clamps.   You COULD use hose clamps if you were just using regular hose to run to the motor, but I think I like the quick-connect setup better, so I’m going to spring the money for those adapters and make it “right”.

Should be a pretty easy deal after about 2 hours of research!

I got a Walbro 255 pump, on ebay… only about 90 bucks for the full kit.  Here’s a picture of it with the wix filter, ready to go:


So I decided to get Russell AN fuel fittings to mate to some high pressure stainless braided fuel line (which will also be used for the transmission cooling lines to the radiator transmission cooling section).  Pretty pleased with this line and think it looks nice, and should hold up well to the heat in the motor compartment.  Pretty inexpensive on ebay, and I got the Russell AN fittings on summit racing.


Hooked it up to the Walbro 255LPH pump, fits perfect!





On to the wiring!