The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 2-bbl or 4bbl for 292?

**67carry-all** · 04-24-2023, 11:33 AM

Hi all - would greatly appreciate your informed opinions and especially experience with this situation. Background: a number of years ago, I replaced the much-despised factory 1-bbl on my ’67 292 with a junkyard Rochester 2-bbl from a 305 V-8. The 2-bbl sits on a homemade adapter on top of an Offenhauser 4-bbl manifold. The improvement with the 2-bbl was tremendous - the big six felt like it could finally breathe, there was more power, and drivability was substantially improved. MPG stayed about the same around 13.

The old 2-bbl is now fairly worn and needs replacement. I’m deciding between replacing it with a similar rebuilt unit vs. a new small 4-bbl such as a Holley 390cfm. The truck is a weekend driver and I’m more concerned with drivability and MPG than power. The motor has an HEI and is otherwise stock. So, what do you all think - 2 or 4bbl?

04-24-2023, 11:33 AM	#1
67carry-all Senior Member Join Date: Jul 2008 Location: Central Coast, CA Posts: 255	2-bbl or 4bbl for 292? Hi all - would greatly appreciate your informed opinions and especially experience with this situation. Background: a number of years ago, I replaced the much-despised factory 1-bbl on my ’67 292 with a junkyard Rochester 2-bbl from a 305 V-8. The 2-bbl sits on a homemade adapter on top of an Offenhauser 4-bbl manifold. The improvement with the 2-bbl was tremendous - the big six felt like it could finally breathe, there was more power, and drivability was substantially improved. MPG stayed about the same around 13. The old 2-bbl is now fairly worn and needs replacement. I’m deciding between replacing it with a similar rebuilt unit vs. a new small 4-bbl such as a Holley 390cfm. The truck is a weekend driver and I’m more concerned with drivability and MPG than power. The motor has an HEI and is otherwise stock. So, what do you all think - 2 or 4bbl?