Just wondering if anyone can tell me the cfm for my carb? I've heard 750 and 800 as well.THANK-YOU!

Are you sure it's a '260' at the end and not a '290' ('290' is a 350ci truck carb- i.e. 750cfm)

If it's definetly a '260' that is within the range for Camaros and Corvettes in 1980 with an auto and a 350ci- again a 750cfm.

Only real variations in 1980 on Q-Jet CFM throughputs (the '80' is the year of the carb in this case- but don't assume the same for other carbs- the coding varied depending on the decade) were 650cfm- California emissions, 780cfm big block trucks, 750cfm- everything else.

At it's core, there are really only 2 basic castings- small primary venturi (capable of around 750 CFM) and large primary venturi (capable of around 800 CFM). The secondary sides are all the same, limited only by how far the air valve is allowed to open in it's stock configuration. If you modify the secondary air valve limiter to allow close to 90* opening you get the full flow it's capable of, regardless of what it was rated at stock.

Look at the primary side main venturi- the part that's actually part of the main casting, not the booster venturis that hang out on the "stalk" in the middle. If the primary venturi is perfectly round around it's entire circumference it's the smaller 750 CFM model. If it's got a distinct "lump" on one side it's the larger 800 CFM model.

Ditto!!

A "bump" in each front barrel = 800cfm and "round" = 750 cfm down in there.

pdq67

Just so there's no confusion here: The 'potential' of the carb is not necessarily what you have sitting on your workbench (or car) right now- if it's a CA emissions-rated carb- the secondary throttle plates will be restricted from fully opening, lessening the max. flow (i.e. 650cfm)- it CAN still be a 750cfm unit- just not "as it is" sitting there. But the 750cfm carb can't become (at least not easily) an 800-ish cfm carb, because, as mentioned, it has a slightly different casting.

Thanks for all of the info! I understand now how to tell the difference.Thank You!! Thank you!!! Thank You!!! gotta love nastyz28!!