BlackSS/SC

I'm in the middle of putting a 01 5.3l & 4l60e in my 99 Grand Cherokee that had a 4.0l in it.

It has a 5/16" fuel pressure line, can I run it or do I need to have 3/8" for sure?

Jimbo1367

yes. 3/8 pressure
5/16 return

themonkeyman89

iTrader: (2)

Yeah, like Jimbo says, you'll need a 3/8" feed line, but I'd see no issues rerouting your existing feed line and using it as the return.

BlackSS/SC

I just have to figure out a way to get the outlet on the sending unit to 3/8" since it's hard plastic and 5/16" I'll reuse the current feed for return.

davev78

I ran into the same thing on my 92 YJ swap, the factory fuel line is 5/16. I think the 5/16 fuel line is adequit for a stock 5.3. At high pressure (60psi) the fuel line size is less important than in the old days were a mechanical pump is located on the block and the feed line was in suction. You can always try it out and if you feel you are lean at high rpm then you can swap the line later.

For the Jeep 5/16 fuel line it is easy to convert to 3/8 hose. Cut the hard plasic line just past the fitting were it was formed onto the fitting, this will give you a perfect od for 3/8 rubber hose. It even has a barb effect to hold the hose on when clamped. This worked great for me.