help Id my holley

this holley ,i have never seen one like it before,shure its a factory carb, would love to know more about it, the numbers on the side are
6R-5610B, and the numbers on the bottom are 6904MB that is all i see on the carb, any thing you have would help....... thanks

 

Where are these #s exactly? Side and bottom doesn't say much. Most Holley id.#s are on the airhorn.

 

From another forum: http://www.thirdgen.org/techboard/carburetors/323934-holley-info-identification-needed.html

Apparently it's a spread-bore type replacement for a Quadrajet. Said to flow 450 cfm. I just googled this up and can't confirm the accuracy.

 

I haven't seen for years, but played with several of them 'back in the day'.It's a Holley 'Economaster' "gas saver" carb produced for a few years back in the early and mid-70's. It's rated at 450 cfm, has mechanical secondaries , but only a single accelerator pump and is flanged to fit a spreadbore 'Q-jet-pattern' intake. It was intended as smog-legal 'fuel mileage improver' replacement carb for factory emissions-control emasculated early-70's engines. It was ok for what it was intended for at the time, but it's obsolete and is not a 'performance' carb of any sort.

Mart3406
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Put one on my wifes Camaro yrs back. It's definitely a non performance piece.

 

I've got one hanging on a nail on the wall in the garage where it will probably stay for a long time.

They were intended as a gas mileage carb just as Mart 3406 said. I scarfed mine up for a couple of bucks at a yard sale and that is the only reason I have it. It might be passable on a small cube V8 or V6 with a Qjet intake if you were looking for a cruiser that got fair gas mileage and weren't the least bit worried about serious performance.