I don't know how accurate the numbers were, but in an article a while back they first bolted on a carbed GMPP intake + 750 Holley to a junkyard LQ4 (and headers of course) and it made 425hp/439tq. I'm assuming you know, but the engine is rated at 300hp from GM.
Test results page for said article:
Another thread with dyno results of a 100% stock LQ4, then tuned:
my best on motor 11.37 at 120.11 with a 1.621 60.and 10.32 at 131.68 on spray cutting gas at 7 gs.no arp rod bolts didnt want to throw a rod.some trans issuses again.need alittle more tuning and right in the 9,s i go.
I think the setup posted is better for stock cubes than the BIG fast intake. Seem like the 90mm or 102mm Fast intake is a little too much for stock cubes. Don't get me wrong there's definite gains, but not as much as a big cube(400cid+) LSx engine. If you're LS1 or 5.3, you would be better off with a LS6 intake or the victor jr style intake.