This turns up all the time. Thought I would start a thread where discussion is about carburetors only.
I have previously published lists of Carter W-1, Carter YF, Stromberg B series, and Zenith 28 and 228 series that can be used on the Chevrolet engines. These lists can be found with a bit of searching.
So in this thread I will suggest pros and cons of the various units, in alphabetic order.
Carter W-1
Availability - excellent
Initial cost - average
Calibration information - readily available
Parts availability - readily available
Carter YF
Availability - excellent for engines up through 1956 (auto choke) and 1959 (manual choke) other than for the 261
Initial cost - average to a bit above average
Calibration information - readily available
Parts availability - readily available (additionally, the YF uses AFB jets, and can use most AFB springs)
Holley 1904, 1920
Availablility - needs research (I do not plan to do any)
Initial cost - needs research
Calibration information - readily available up to about 1961
Parts available - spotty
Rochester B
Availability - readily available for all except 261
Initial cost - DIRT CHEAP!
Calibration information - spotty
Parts availability - readily available
Rochester M
Availability - needs research
Initial cost - DIRT CHEAP
Calibration information - very little available other than gasoline jet size
Parts availability - other than rebuilding kits, poor
Stromberg B series
Availability - excellent
Initial cost - above average
Calibration information - available, but you have to look
Parts availability - readily available, but only from certain vendors
Zenith 28 and 228 series
Availability - fair
Initial cost - above average
Calibration information - mostly available, but you have to look hard
Parts availability - fair to average
Foreign known makes and modern imitations are not covered because:
Availability - good on many
Initial cost - ???
Calibration information - NOT AVAILABLE
Parts availability - POOR
A comment about the Holley progressive 2-barrels. About 25 years ago, the progressive 2-barrel Holley carbs were being "blown out" by the manufacturer. We had WD status with Holley at the time, and our cost on new units was $5. each! Because they were so ridiculously cheap, we tried a couple, but the issue was the 2->1 adapter. To even get close to the efficiency of a single barrel, we found through extensive testing that the adapter had to be at least 4 inches tall, and machined for a smooth transition; and we still could not make the Holley progressives work as well as a Rochester B. I gave ours away. So:
Holley progressive 2-barrel
Availability - Don't know, but guessing available
Initial cost - cheap
Calibration information - as far as I am aware, not available. Certainly not in any of my Holley books
Parts availability - other than kits, POOR
Personally, when looking for a carburetor (I have other than original on all my collector vehicles other than one that is absolute 100 percent as built (at least externally

), my criteria is as follows:
Calibration information (if not available, then I don't want the unit!)
Availability - I should be able to find one within 6 months.
Since I do so few, initial cost is not a concern (within reason...one of my collector vehicles has a $1500. 4-barrel, another has a dual 4-barrel set-up)
And since I have tooling and experience to make any part other than castings, parts availability is not a concern.
Both of the above have been on the vehicles for at least 20 years, without problems. I like to do it once, and forget it.
Jon.