Without going for something mail order or off the net, the only way to get one locally is buy the whole rebuild kit. I needed one for a 2100 the other day. A cooperative parts man tried every sort of lookup we could think of and got nothing except a $37 carb kit.
A few years back I remember AutoZone used to have them individually packaged in the "Help" section. The "Help" catalog doesn't even list them anymore.