my buddy has a fuel hose issue, his sending unit for the main line has the threaded doohickey on it, its 7/16th we believe, we need some kind of adapter to thread onto this so we can clamp a rubber hose over a barbed fittings preferably, so we can clamp the other end of the rubber hose back over the stock metal fuel line running up to the motor.

does this make sense? im having trouble finding the correct parts on summit to make this work, would our main fuel line be a 3/8 or 7/16 hose?

3/8=-3an right? and if so is 7/16 same as or close to a -4an?

im not sure if i need a 7/16th to -3an or -4 an barb to make this work correctly, please help me out.

 

Not sure quite where you're talking about/what you're doing but 3/8" = -6AN as far as I know. All the time's I've ordered parts for my fuel lines the two sizes were interchangable.

 

is our main fuel line a 3/8 or 7/16?

 

Should be 3/8"

 

3/8" is the size of the main feed line on most GM cars of this vintage. Next size up would be 1/2". The threaded fitting could be significantly larger, but the line itself will be 3/8". Return lines are slightly smaller at 5/16".

FYI- 3/8" rubber hose fits over 3/8" pipe (hardline).