Does anyone know what the port at the top rear of a quadrajet carb connects to ('86 Suburban)? I removed my aircleaner and discovered a connection near the top of the carb and facing towards the firewall with a short (2") piece of vacuum line (about 1/8" diameter) attached to it. I cannot, however, figure out where it originally tied in - there are no obvious loose hoses in the vicinity. Could this just be some sort of overflow? If anyone knows, I'd sure appreciate hearing about it! Thanks.