[1] The Perf intake provides a slight improvement over stock when properly used.
Properly used means that the rest of the engine components combine to make peak HP at 5600 rpm [ in a 318 ] or less. Some idiot will try & use the Perf on a 6500 rpm engine, & then blame the Perf for lack of top end....
[2] Holleys. Sigh. If they are so good, why is every man & his dog making better ones....When Edel copied the Carter AFB, they changed NOTHING because the design was perfect from day one....
[3] Some little known facts. Edel used to sell Holley carbs before they started making the AFBs. Holleys then got dumped. At the time that Edel was selling Hs, they compared a 600 H vac sec to a 600 AFB on a 350 Chebby. AFB made 17 ft/lbs more tq, 17 hp more & used less fuel doing it. Nuff said...