does anyone have a part number or know which transmission line I will need for my 4l80e swap? I spliced the back trans lines that goes to the port closest to the back of the truck. I need to know what hard line I need. I got on rock auto and there are so many different kinds, I don't know which one to get. It's the line that goes from the radiator to the back of the transmission. can anyone help??

 

For the 4L80E in 99-07 classic.

***Disclaimer*** The part numbers will be different if your 4L80E transmission has the 2 ports close together like on the 4L60E. Always verify with the dealer for your application before ordering.

1st Design part numbers
15717834 Hard line - Front port of trans to top of radiator
15710129 Hard line with rubber hose- Bottom of radiator to cooler behind grille
15812029 Hard line - Rear port to cooler behind grille

2nd Design part numbers
15812029 Hard line- Rear transmission port to transmission cooler behind grille.
15267484 Hard line- Front transmission port to bottom of radiator
15809057 Hardline with rubber hose- From top of radiator to cooler behind the grille


I would go with the Second design lines as it's the more efficient way of routing the factory lines.