Best Carb set up for a 300 four barrel

E

ex-probation-parole

Member
I have a 66 skylark with the 300 ci 2 barrel that i am going to covert with a 65 cast four barrel manifold. I am running a 350 turbo trans so am not to concerned with the kick down set up. What is the best way to go? Stock carb or aftermarket? Simple and easy is also a consideration, something not to extreme for a daily driver. Thanks for your opinions, or pit falls to over come if you have already done one.
 
Unless someone actually put in a 4barrel and ran it on a dyno no definite way to know if it was better or worse than stock. These cars with no computer control forgive a lot in way of performance if it is not good match. But you can get close to stock because the factory carb was exclusively chosen to match the performance of the 300. What is the CFM of the four barrel that was factory used on the 66 or 65 with 300? That is your starting point, the CFM, one of the most important carb's performance factors. Once you discover this it will be easier to shop for a carb.

1966 Buick Chassis Manual, FREE ONLINE
 
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ex, if this is a driver and not a show car, you might look into EFI. Not for everyone, I know. I did the EFI 12years and 26,000 miles ago on my 1950 straight eight. No way I would ever go back to a carburetor. And you really do not need to go to a 4 barrel. Just my opinion.

Ben
 
Thanks for the info. I am looking for something with a electric choke that I don't have to prime to start after sitting for one or more days. I am not after the high performance aspect of the change. Something that the little woman can get into, start. and go with out trouble.
 
firstofeight said:
ex, if this is a driver and not a show car, you might look into EFI. Not for everyone, I know. I did the EFI 12years and 26,000 miles ago on my 1950 straight eight. No way I would ever go back to a carburetor. And you really do not need to go to a 4 barrel. Just my opinion.

Ben
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EFI is a great suggestion. Can you tell us about the fuel system upgrade that complemented it?

https://www.holley.com/products/fue...2-barrel_systems/sniper_efi_2gc/parts/550-866

Features:​

  • Bolt on Rochester 2GC small bore two barrel carburetor replacement
  • Installs directly to the factory Rochester 2GC small bore intake manifold, no adapter required
  • Engineered to fit 1955-1969 GM vehicles that utilized the Rochester 2GC small bore carburetor
  • Designed to fit most factory 2GC air cleaner assemblies
  • Universal throttle lever with TH350, 700R4 & 200-4R kick down provisions
  • Throttle body mounted ECU – no extra boxes to mount
  • Not designed for Tri-Power installations.
  • Supports up to 350HP with Two 100lb/hr Injectors
Most of the 4 barrel EFIs I'm seeing are designed for up to 500 or more HP. Too much for just a driver. This setup just happens to be designed behind the 2GC.
 
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If you follow the link BOB shared with us you will see the various options. If you are going to put in a 4 barrel carb just be aware that without research, you may need to swap out jets to fine tune the carb you selected. Other option is if you just need to go up on the jets you would drill jets out. Having access to a four-gas analyzer will assist you in accomplishing this and many of the "genuine true automotive shops" will have one. I have attached the link 14.7:1 that has the parameters for you to dial that carb in. In summary you want a carb that is easily tunable.

14.7:1
 
GL03 said:
EFI is a great suggestion. Can you tell us about the fuel system upgrade that complemented it?

https://www.holley.com/products/fue...2-barrel_systems/sniper_efi_2gc/parts/550-866

Features:​

  • Bolt on Rochester 2GC small bore two barrel carburetor replacement
  • Installs directly to the factory Rochester 2GC small bore intake manifold, no adapter required
  • Engineered to fit 1955-1969 GM vehicles that utilized the Rochester 2GC small bore carburetor
  • Designed to fit most factory 2GC air cleaner assemblies
  • Universal throttle lever with TH350, 700R4 & 200-4R kick down provisions
  • Throttle body mounted ECU – no extra boxes to mount
  • Not designed for Tri-Power installations.
  • Supports up to 350HP with Two 100lb/hr Injectors
Most of the 4 barrel EFIs I'm seeing are designed for up to 500 or more HP. Too much for just a driver. This setup just happens to be designed behind the 2GC.
Click to expand...
Thanks for this great contribution! I knew about the 4 barrel EFIs, but the 2 barrel one slid by when I wasn't looking. It's great to learn of your years and miles with it.
 
ex-probation-parole said:
Jegs list this kit $ 1250.95 but has none available. Then if you want the distributor and fuel pump that's all extra. My pocket book says to go old school.
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My toys allowance doesn't stretch to that extent, either. Maybe I could do 10% of that, then add 40% for Canadian dollar exchange. Then add, as you say, the other necessities. (Sigh - carb it remains, then.)
 
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