Using an lq4 truck engine with the truck intake (03),what size return line will I need to use with the truck regulator fuel line. Will 1/4" line be OK?...
Rick

 

I don't see it being a problem.

 

I''m not 100%, but I'm pretty sure that all the LS series engines need at least a 5/16" return fuel line to the tank.

 

For some reason I remember the feed being 5/16, and the returns being 1/4.

 

stock return is 5/16"

 

I know the '99 & up Vette fuel filter/regulator is 3/8" supply, 5/16" return. Which was the same sizing as my bone stock 1996 GMC pick-up truck, with a 4.3 V-6 in it, had for standard steel tubing fuel line sizing. Not sure, but if my memory recalls, these were outside dimension tubing sizes. Which I remember as being odd, because hose, etc...is always measured as inside diameter. Just pay attention to this when buying fittings & hose.

 

Yeah, that's what I recall as well. thanx

 

K I guess the Trucks are different from the Cars..or I keep remembering the wrong sizes..

 

Thanx, 5/16" it is.. Ive added a 3/8" fuel line, guess I'll add a 5/16" return.
Rick