Amazing that the Chinese can sell a new 2BBL for $109 w/ free shipping. The photos look fine w/ yellow-chromate plated steel parts. My main concern would be if the gaskets and diaphragms are of quality rubber since I've had Chinese products which used what-ever plastic which soon degraded. The BBD is a simple robust design, easy to adjust. A pdf manual has been posted here several times (or links). I think the common Edelbrock 4 BBL after-market carb is about the same design (metering rods). I don't think the BBD has many places to leak fuel from the bowl, like many Holleys can. I suspect their description "vacuum choke" just refers to the little vacuum "choke pull-off" at the top. Its purpose it to let you set the choke full-closed for easy starting, then as soon as the engine spins and builds vacuum, it pops the choke open a little more to not stall. Many people don't know their diaphragm failed (easy to test), so are constantly fooling with the choke setting. I suspect the choke in this one is still operated by an external rod from a temperature spring in the exhaust (w/ kludgy electric heater add-on of later years to open faster).
Someday, a company may offer an integrated EFI throttle body system for 2 BBL manifolds <$1000, so this new carb would suffice until then. I don't know of any, and most/all TBI systems sold today are too large for a 6 cylinder, though perhaps you could swap in smaller fuel injectors since many use standard MPFI injectors, but would also need a 4 BBL slant intake (Offenhauser, Clifford, or Hurricane).
