I do not know about the number, but it has a large bowl in the front and rear, so it has to be from a GM car with 4 wheel disk brakes. I will put money on it that it came from a Corvette. Go to Rockauto and look up a 1972 Corvette with manual brakes and you will see quite a few options. The are in the mid $20 range.
You will need the list number to buy the correct kit unless they are selling a super generic kit. You carb is pretty nice since you have metering blocks int he front and rear. You might want to pick up a set of jet extensions for the front and rear and a cam kit. You can really make them run with a bit of fiddling.
https://www.holley.com/products/fuel...parts/122-5000