If the 2100s is readily available I must have been looking in the wrong places. I did eventually locate one after looking for a while. Rebuilt it with a kit from Carbking. It seems to be working perfectly but so was the Rochester I replaced. I guess I had a good one (I used the best parts from 3 to rebuild it originally). So far I can't detect any advantage to the Carter. I hope to see better fuel mileage but keep forgetting to note the milage at fillups.