I am running a 2004 LS 1 Gen 3 and I went with the Hurricane from Old Air out of Texas. What I like about this system is it utilizes the factory radio speaker grills in dash as 2 large AC vents. I then opted for 2 small 2" round chrome looking under mount vents that mount on bottom of dash below head light switch and one on far passenger side. 4 vents total. plenty of cooling power . Most important for me was I wanted-Everything is hidden under the dash. I went with mechanical controls that can barely be seen. The AC compressor mount bracket was a whole different story.( I finally went with ICT online for accessory brackets) I bought 3 different set ups for my accessories before I found something that would fit correctly. Make sure that you use the small sanden compressor. (I forget what model?) your challange with the LS will be your accessories clearing the fenders etc.
Here is a link to Old Air:
https://www.oldairproducts.com/produ...omplete-system