This is a pair of Barry Grant RS (removable sleeve) carburetors for use on a roots blower (supercharger). According to the chart I have posted, these have the black sleeves installed which make them flow 975 cfm each. I have been running these for 8 years on a 10-71 supercharger on a big block Chevy and they have worked flawlessly. The base plates and metering blocks are made from billet aluminum. There are no vacuum fittings except the ones to boost reference the power valves. I have run a power valve in the primary side only, but both metering blocks have a provision for one.
These carburetors are fairly rare and getting harder to find. When these came out the premise was that you can buy 1 main body along with a sleeve kit and be able to change the carburetor size from 600-1025 cfm simply by changing the sleeves. A great idea and ahead of it's time in my opinion. The previous owner was running these on a drag boat and had them powder coated to match his paint scheme. There are some small chips in the powder coating, but they are only cosmetic.
As I stated before, these worked flawlessly on my engine for the last 8 years. The only reason I am selling them is because I am switching over to run E85 and I purchased new carbs specifically built for running E85.