Gen III truck intakes, I have 2 very different intakes from LM7/LQ4/LQ9 engines that I am very curious about yet in my searches over the past several months have yielded nothing concrete. Hoping to get some answers from those in the know, (not just random hypothesis or theories without any substance to support such...)

The Ugly truck intake we al have seen and read about, came on the 4.8, 5.3, and 6.0L. There is another truck intake, much more aesthetically pleasing with a totally different air flow tract entering the heads, similar to the car intakes, just much taller and appears to be longer runners. This one pictured came form a '02 Chev 250 Ext Cab 4wd 6.0L pickup, (the LQ4 it was on top of ended up in my BMW M3).
Soooo, what is the difference between these intakes on stock 5.3 and 6.0L as seen on dyno and MPG?
The ugly manifold has part number 25344062 in its casting. The "pretty" version has NO casting numbers in it, and is a two piece design that can be disassembled, floor removes from the rest of the plenum/runner section.