Pontiac installed a 4 bbl carb on their over head cam 6's way back in the 60s and those motors ran really really well. What some manufactures use to call called compound carburation was in fact multi carbs on an inline motor and those designs ran really well (Hudson comes to mind). Some designs were better then others. Some set ups ran better then others. I have run quite a few multi carb set ups through the years on some of my inline motors. The wicked and unreliable Rochesters, the better then good Carter YFs, the pretty decent but hard to find Holley glass bowl 1908 and 1920s, Holley webers, webers, holley 2 bbls, holley 4bbls. some worked better then others.
I like multi carbs and they have always run better then my stock single bbl carb. How do I know? I have the benefit of still owning my first car and know how it ran (at a drag strip) before I began modifying the 235 that was in it, and after over a period of 44 years. I have run 235, 261 250 motors in cars and trucks. All benefited performance wise from additional carbs. If I was just building a stock motor I would likely leave the single 1 bbl. But I like to tinker. Recently, I was running Holley/Weber Ford Pinto 5200s and they ran good. I most recently ran a pair of real Weber 38 DGEV carbs, they ran pretty good but I always got the feeling there was more.
I just got done installing a pair of 2300 350 cfm Holley's on a 261 chevy. Runs terrific, absolutely terrific. No lean off idle stumbles, it is not running rich, no coughing or stuttering at idle, no loading up, gets to 5000 rpm in a heartbeat.
I just don't get this constant theoretical discussion poo pooing anything other then a single bbl carb and that a single bbl carb is the ONLY carb that should ever ever be used on an inline stovebolt 6. Hogwash. If that is your choice then fine but the fact remains that the inline 6 responds like any other motor to more cam, more carb, better ignition, better performance. It may not be gobs and gobs of improvement but a good thoughtful selection of parts, including carb, will give performance improvements no matter how modest. To simply write off a good multi carb set up as worthless or a good four bbl carb set up as ridiculous (notwithstanding that Pontiac did it for proven performance reasons) is just being closed minded.
All right, lol, I am off my soap box.
Last edited by Dragsix; 07/23/2021 8:01 PM.
