I have a 6.0 Chevy LY6 in my Burb. Here is an interesting article praising the LY6 (which I liked) and discussed how to turn it into a high performance engine. All you Chevy fans enjoy.
The truck intakes actually flow better then the LS3 intake so it's more of a cosmetic or height reduction upgrade. Also the dyno numbers are 60's style fantasy numbers as they run the engines without an air intake, air filter, alternator, water pump, power steering pump, muffler, resonator, etc so even a stock engine will blow past the SAE numbers easily.
That's good information there. I've been thinking of doing a mild port on my 06 Sierra Denali LQ9.I much prefer Cathedral style heads on a truck engine.....It's not about peak flow numbers. A set of mildly ported "317" LQ4/LQ9 cylinder heads with the right Quench will outperform a "823" rectangle port head in under the curve power/torque production every time.