The Stovebolt Site Forums The Parking Lot Big Bolts 4 barrel intake manifold

I have a lot more gear in my 2-ton (& a lot more booty to haul too!), but my 270 pulls real nice uphill in original trim.
I have a stock manifold and the factory spec Holley single barrel, and it pulls pretty well in mid to high RPMs. Myself, I dont think the 270 breathes hard enough for more than a 2bbl, the volume of air going into the carb needs to be enough to keep the air velocity high enough for the jets to function properly.
Having over carbed an engine or two, I can say that typicaly you only see the improvement at high RPM, and the rest of the time you're just sucking fuel down like mad. On my particular application (desert racing motor) I was running in high range most of the time so it worked out OK, but for day to day driving not so much,...