I've had GREAT success with Carolina Carb rebuilding my original 1 BBl. They have a flow bench that is great, no adjustment required after carb is rebuild. Put it on, connect gas line, tap accelerator, pull choke, motor starts. Send them your carb, same one comes back to you rebuilt.
http://www.mycarburetordoctor.com/

1958 Chevrolet 3600 NAPCO 4x4 Apache
"Calvin"
In the Stovebolt Gallery