That top small line the overflow line to the overflow tank. The nipple on the radiator is most likely cracked. If you pull the fan shroud (6 screws) and fan assy + 1 connector, then take off the large radiator hose. Loosen both clamps and slide it aft on the s/steel pipe.
You should have access then.
This thread link I listed a few Alt radiator part numbers.
Hello, new here, question about Az Heat
I see you have the dual 10" fans. If you want to do an upgrade the Mishimoto Raceline 10" fans push 1600 each and are pretty much plug and play. (drill new mounting holes in the shroud). I'm rock steady in traffic above 100F summer days
https://www.mishimoto.com/race-line-...ow-fan-10.html
https://mishimoto.com/media/addition...ans-sizing.pdf