My swap came from an '02 TransAm,
I used the factory steel lines up to the front of the oil pan and brazed on -6 AN fittings.....
from there to the radiator with teflon braided hose, from the radiator to an auxiliary cooler and back with 3/8" aluminum lines.
the line to the cooler comes out at the top of the radiator, the return comes out at the bottom and back to the transmission
painted all the lines black to help them disappear