Do dual quads on a small block really suck?

Do dual quads on a small block really suck? (No pun intended).
Dual Quad manifolds are few and far between for the Mopar smallblock....yet they are readily available for 289 Ford and 283 Chev....and most reports I've read state a good single quad or six pak will outperform a 2X4 setup. With proper sized and tuned carbs, does it make any sense that a smallblock Mopar should be any different than any other small-cube motor running 2X4? Anyone have any track experience to back this up? Thanks.