What carb is on a 73 198?

You need to get under the hood and check. I believe the numbers are on the back, at least if it's a 1920. There are lots of numbers there and they may be hard to read so you may need to clean the carb and use a mirror to see them. I looked the whole carb over and wrote down any number I could see and brought the numbers to my parts guy. Turns out it was a 1920 and I got a kit for it by Hygrade. Came with everything but the float. $53 bucks.