Chevy_man_88

I got a Rochester dueljet non electronic control, which is better and got more cfm, the TBI or The 2barrel dueljet?

Berlinetta00

Whichever your engine runs with is the only real answer.

The older TBI models had fairly good flow as I recall but the other design issues really prevented a whole lot of performance. Assuming you have a V8, No 2 barrel carb out there for automotive engines will out flow or out perform the stock TBI (someone is going to post a pic of a ridiculously stupid and large carb set up for a hydroplane or something that outflows a TBI- good luck fitting it under the hood of a third gen). Get the factory TBI running well or swap to the four barrel of your choice, but a two barrel is a step backwards.

makaveli09

The tbi flows from420-470 from from what I read at different sources.As for the 2bbl Rochester I am not sure.I know Holley has 390cfm and 500cfm 2bbl.

Schurkey

DualJet? That's the front half (primary) of a Quadrajet. You know, the carb with the TINY ITTY-BITTY throttle bores.

There are two CFM sizes of Dual Jet, but several different models. CFM is "Small" and "Even Smaller". Wild-asz guess: the 305/350 TBI outflows a DualJet by double Maybe more than double. Some were the same physical size as a Q-Jet, but there was no opening secondary system. Others had a dedicated 2bbl housing.











The DualJet is horseshit for performance. Nice for economy on a small enough engine, though.