Even if you can’t find a someone who can rebuild the carb…there are aftermarket companies that still make/sell carbs for these cars. Eldebrock, Webber, Holly. And if you want to you could also put an aftermarket fuel-injection system in.
You are stealing thunder there with your observation that float problems existed BEFORE ethanol.
I drove a smallblock with a Edlebrock performer carb for over 10yrs on fuel with ethanol,not one problem. Perhaps there were brass floats in it but as I said nothing motivated me to open up the carb.
Define “crusty”. 
You can replace a feedback carb with a traditional one. But you will most likely have to replace the ignition system for a simpler, standalone unit.
Hey Mike, do these aftermarket systems work good?If I ever build a Hot Rod I sure would like F.I. on it-Kevin
A crusty mechanic:
- has a shop that looks like a dump, but can locate anything in a matter of seconds
- has a timing light
- has a dwell meter
- owns that tool to adjust GM points through the window on the distributor
- has a politically incorrect calender hanging on the wall
:o)
I’ve used two before…worked fine.
One was a Webber…the other a Holley.
The Holley was a direct replacement…Perfect fit with no screwing around.
Had to do some modifications to get the Webber to fit…But it wasn’t that bad.
Once installed…they both worked flawlessly.
Understands how a thermal choke operates.
Understands how a primary choke pull-off operates.
Understands how a secondary choke pull-off operates.
Tester
Where do you live that you can get gas without ethanol? Everything where I live (western NY ) has 10 percent.
The federal government, that’s who sez.
Now, if you don’t live in a state that checks, well…
That 67-68 Eldorado would be a great car. Holley makes a FI system that you could swap in if the carb proved troublesome: http://www.holley.com/502-20S.asp
I grew up with cars with carburetors. We were taught that “carburetor” is a French word that means “leave it alone”. In other words, look for other causes for problems. In those days, at least 80% of the problems were with the ignition system and not with the carburetor.
Something else to remember is that the fuel system and the carburetor are two different things. Carburetion that is not right doesn’t necessarily mean that something is wrong with the carburetor. I have a 1978 Oldsmobile Cutlass with a 260 cubic inch V-8 engine and a 2 barrel carburetor. If the car sat for more than a day, and sometimes even less time, I would have to prime the carburetor to start the engine, but then it would seem to run fine. The accelerator pump wouldn’t squirt any fuel until I would prime the engine and get it started. Then the accelerator pump worked fine. I changed the fuel pump with no luck. I had people tell me that the carburetor was leaking gasoline internally out of the float bowl. I tracked down an old time mechanic and he found the trouble–a neoprene section of the fuel line had deteriorated down by the fuel tank and the car was sucking air. When I would get the engine running, the fuel pump would work well enough to suck up the fuel from the tank. However, the starter motor couldn’t turn the engine over fast enough to supply fuel to the carburetor. This was a carburetion problem but not a carburetor problem. Find a good old-time mechanic who understands the old fuel systems and you will be fine.
I was thought not to touch the double carbs, but for the regular ones we used to mess with them all the time. Nobody is sure if we made things better or worse, it was kind of a combination of a tune up machine work and then ear/feel thing.
I did rebuild a carburetor once. This was a one barrel carburetor on a 1950 Chevrolet pick-up truck. It was the simplest carburetor imaginable–even had a mnaual choke. It took me 4 hours to get it right, altghough it worked fine when I finally installed in for the second time. Back in 1959, I watched a master mechanic at a dealership that handled Buicks and Studebakers install a fuel pump on my Dad’s 1954 Buick in one bay and rebuild a carburetor on a 1959 Studebaker Lark 6 in the next service bay. He finished both jobs in less than half an hour and called for more two more cars to repair. He had the carburetor off the Studebaker and the parts in a solvent bucket while he was waiting for the parts person to bring over the fuel pump from the parts department. He had the pump on the Buick and the Buick ready to go. While he was waiting for the person to drive the Buick out of the bay, he had the Studebaker carburetor back together, on the car and was making the final adjustments.
Well if you live in the sticks,are they really that strict on the old jalopys?I’m thinking late seventies-Kevin
True,I always assumed 90%-Kevin
This is for Mike,trying to thank you for your reply,but the system wont let me-Kevin
E10 was not your problem. I understand that you really think so. E10 really does not cause the problems. Peace.
Ethanol does not affect the carb float at all. Does not happen, it is basic chemistry. sorry that you think it does. Peace.
That’s amazing! Without having ever seen my car, you are able to rule out a diagnosis for a problem I had more than 10 years ago.
At the time I had a really good mechanic, and the problem with the carb was with a rubber fitting that kept disintegrating.
Who would you believe? I think I will stick with the trusted mechanic who rebuilt the carb rather than some faceless person on the internet who thinks he can rule out a diagnosis without even looking at the car.
Think about what makes a car a flex fuel vehicle. It is the absence of rubber parts in the fuel delivery system. Ethanol damages these rubber parts.