[DMXF]

Depends on what single four setup you're comparing it to. From everything I've ever seen, a well setup weber small block will make perhaps 30, 40 or more peak HP than a period 60's 1x4 Holley induction equipped one. If you have a ported modern spider type single plane intake with a worked very large venturi Holley, they may be similar in peak HP. All the old Shelby American literature clearly documents the webers as being far superior, including more peak HP.....why do you think Shelby American ran webers on all of their team race cars? One notable advantage of the webers is they start off with much more uniform cylinder to cylinder mixture than a Holley induction. Formula 1 engines ran webers and then moved to IR fuel injection, the evolution of IR. If plenum type systems were superior in any way, wouldn't you think the F1 teams would have jumped on it a long, long time ago?