Is a FAST 102 intake worth it on an LS3?

On LSX Magazine's back-to-back test of a modified LS3 street engine (CNC LS3 heads, COMP cam, long tubes, factory PCM), the FAST LSXr 102 mm made a modest gain over the stock LS3 intake:

Intake	Throttle body	Peak hp	Peak lb-ft	Notes
Stock LS3 (GM Performance)	102 mm Nick Williams (intake port sized for 92 mm)	556.3 @ 6500	497.2 @ 5500	—
FAST LSXr (LS3)	102 mm	566.3 @ 6600	515.3 @ 5200	+10 hp / +18.1 lb-ft; fits stock-hood envelope; polymer
Holley Hi-Ram (300-117)	102 mm	605.4 @ 7000	496.7 @ 6100	+49.1 hp top end, loses midrange; won't fit under a stock hood
Holley Mid-Rise (300-135) w/ Hi-Ram top	102 mm	555.0 @ 6900	483.3 @ 5700	Lost power vs stock on this NA EFI build; designed more for dual-quad/boost; 10.44 in tall

Takeaway: the FAST LSXr picked up about 10 hp and 18 lb-ft at peak over the stock LS3 intake and still fits under a stock hood. The tall Holley Hi-Ram made the most top-end power (+49 hp) but lost midrange and won't fit a stock hood, and the Mid-Rise lost power on this naturally aspirated EFI combination.

On a stock LS3 the gain will depend on the rest of the combination — this test engine was already cammed with ported heads. See the heads & intakes guide.