Probably because a single four barrel in the right hands is usually quicker. Especially on a street build.
single 4 better on a street build? i have doubts. single 4 better at the track; maybe. modern manifold technology favors the single carb for peak power, but not a broad power band. has any single 4 race set-up made more power than a 2x4 tunnel ram? i think there are too many variables. people in general just embrace single carb stuff because the culture has told them to.
i still think some of this boils down to most folks can't tune 1 so why do they want 2 or 3. i think on the street multi carb is far more versatile than any single 4 could ever be.
I think that is the key. Especially when talking about primarily street driven combos and the 'average' car guy.
Whether we're talking way back then or now, frankly very few guys can do much (if any) tuning on a carb. More carbs means more complexity and intimidates most guys. And that most certainly plays a role in the rush to the antiquated throttle body EFI kits today. 'Self tuning' is a huge draw when you want to 'bolt it on and go'.
And because of the intimidation factor, the demand for carbs, manifolds and collateral pieces for multi combos is less. So, there are more parts for the single set-ups.
As to "on the street multi carb is far more versatile than any single 4 could ever be", that is simply not true for the 'average' car guy if for no other reason than the inability to tune. And I haven't seen a lot of testing each way to prove that conclusively for the guys that can tune them. Certainly, there are combos that would favor one or the other individually, but saying that multiple carbs are always or even usually superior, faster, or more versatile is way oversimplifying the subject, at least in my opinion.
And correct me if I'm wrong but outside of the Hemi, wasn't a big part of the multiple carb factory offerings the fact that there weren't any single carbs big enough? That and the marketing side of it? Not so much for the superiority of multis over singles?
