In the engine bay of my 1985 XJ6, there are two steel fuel lines. One is on the right side (air intake side) and the other is on the left side (exhaust side.) The one on the right is the high pressure fuel feed, and the one on the left is the return line.

My question pertains to the steel fuel line on the left side. What size is the barbed fitting on fuel line on the left side of the engine bay? I installed a 5/16" hose on it years ago, but IIRC, it was a fight to get it on. I am thinking that it may actually be a 3/8" line. Does anyone know? Has anyone used a 3/8" hose on that fitting?

FWIW, I know that the tubing and hoses on the return side at the back of the car are 3/8".

My car has an LS1 V8 engine. My goal is to use a 3/8" hose on that hose barb fitting. I want to fish around for the correct answer before I start cutting away at my fuel system!

 

Memory, haha.

Those 2 barbs are 9.5mm, so 3/8 "should" be fine. I would also suggest using the EFI spec clamps to reduce damage to the hose from the standard worm drive slots.

 

Excellent - thanks for the info!