RE: K+B with Irvine Carb
Sometime around 1979 to 1980 I bought a brand new K&B .40 that came equipped with a grey plastic Irvine carb. No pump. It worked perfectly. Shortly after that, K&B started shipping engines with their own metal carb, but it wasn't the Sportster style metal carb. It looked as though it were carved from a big block of aluminum. They worked just fine too.
Ed Cregger