I'm thinking of replacing my factory quadra-jet carburetor. While I don't understand the little differences between my carburetor and one that came on V8, I do know that all quadra-jets of this time were 750 cfm. This seems like a ton of cfm for my 250ci engine.

I'm wanting a Holley carb (just because). Holley's initial suggested replacement is their 0-8007 390 cfm square bore carburetor. Their 0-80555c 650 cfm spread bore carburetor is a quadra-jet replacement. Which of these or any other is a good replacement?

I'd like to go with a square bore. Maybe I could use it on a future V8, but not the dinky 390 cfm one. Doing so will require an adaptor. Simple enough but this raises the carburetor ¾"-1". Would this create any issues with linkage or hood clearance?

Any thoughts y'all have on replacing a Sprint carburetor will be appreciated.

I had my Sprint carb rebuilt by Cliff Ruggles and it made a huge difference. I am not sure exactly what he did but it is almost night and day. I told him my car was staying stock and I wanted the best possible performance out of it. He is not cheap and has a very long backlog but I am very happy. However, I would bet the dollar difference is not all that great between his rebuild and a new Holley.

BTW whatever you do, do not throw away the stock linkage, it borders on being priceless in the Sprint market. Very, very, very tough to find replacements. Let me say it again, very hard to find replacements. Manifolds are a dime a dozen, linkage and air cleaners are the real money makers if you can find them.

I'm not getting rid of anything I take off of the car. I also want any changes reversible. I would imagine that rebuilding my quadra-jet would be just as good - maybe even better than - as buying a new carburetor.

I ordered Cliff Ruggles' quadra-jet book. I'm not against keeping the old quadra-jet.

>all quadra-jets of this time were 750 cfm< (Even if it were an 850, it wouldn't matter.)

That’s available cfm. Many people don’t understand how quadrajets work because it’s physically impossible for a quadrajet to be too big of a carb for any engine.

I’ve retired from technical conversation, an occasional consultant at best, so I’m not going tech on the subject. Overall function: The quad is a self regulating fuel delivery system. Engine demand, not throttle plate position, determines fuel/cfm delivery; simply, if the engine is only able to intake 350 cfm of air, the quad will limit airflow 350 cfm. And if you understand how they work, they will bring out the best of any engine that is able to consume 750/850 cfm of air.

I guess I'm not understanding why you want to make the change in the first place.

I'm wanting to correct a problem. I'm guessing at this point that replacing the carb is an easy solution. Knowing what to replace it with isn't necessarily as easy. I sent a contact request to Ruggles inquiring about a rebuild. Rebuilt or new, either way I need a 'new' carburetor.

Excellent info Amervo. I always wondered how they were able to make the carb go across so many engine types.

Wow hokie1984, I contacted Ruggles and he has a 9 month wait! I'm also waiting to hear back from SMI-Sean Murphy Induction. Perhaps their wait list is shorter to non-existent. Based on your Ruggles lead I've decided to definitely reuse my original carburetor and not replace it with something different. Thanks.