55 bel air carburetor trouble better to upgrade?

Hi guys im fairly new to owning a classic car. My family is really big on the classics. I am currently working on a 55 bel air 4 door with a 265 and 350 transmission. My dad owned this car for a long time along with many others but it wasn't used for atleast 15 years so it sat in the driveway. As soon as i graduated highschool and started working i wanted to fix it up so me and my brother finally got it started and ran fine for a few days untill a number of problems surfaced. The carb began to flood and then it was rebuild and the flooding it stopped however when i put it back together it would have a lag when whenever i pressed the gas pedal. i heard it might be the accelerator pump so i just put the original one back on thinking i might have gotten a defective one and the lag was gone but it began to flood again. I have taken it apart multiple times and cleaned it but i was wondering if maybe just getting a new upgraded carb would be best. It currently has a rochestor 2 jet. Everything but the transmission is stock so i wanted to upgrade to a 4 barrel carb with a new intake and i had this one in mind. i just wanted to ask if this would be a good idea? any possible problems i may encounter? Any help is greatly apprciated Thank You
https://www.summitracing.com/parts/edl-2021/reviews/?sortReviews=Newest

 

No answer, information only for your decision.

Carter Carburetor, who made 4-barrel carburetors for many Chevrolet applications, suggested:

265, 283 - 400 CFM
327 - 500 CFM
350 - 625 CFM (square-bore) or 750 CFM spread-bore

Jon.

 

would there be problems with getting a 600cfm carb? i heard getting to high would cause gas mileage to go down

 

I don't believe you would be sufficiently happy with the drivability of the vehicle to even think about fuel mileage.

However, if you decide to do this, a suggestion:

Put the 2-barrel Rochester back on, then with the help of a friend with a stop watch, run 3 wide open throttle 0-60 runs, and calculate the average E.T. Then, once you have installed the "upgrade", do the same and compare the results. I think your results will not be what you are currently expecting. But if you run the tests, you will have positive proof.

Jon.

 

Thank you for your advice!

 

Get the carb rebuilt by a professional . [some even dyno them] and upgrade to an electric choke.
A 265 is quite responsive with a 2 barrel.

If you want it to be responsive and economical spend the $$ on a 2004r trans.
It is only 1/2" longer than a T350 [same length as a long tail powerglide]

But 1st gear is 9% lower [ the same as going from 3.7 to 4.0 gears] and you have 0.67 overdrive

You can recover $$ selling the T350