That MAY be an original (non-rebuilt) Q-Jet. Is so, you have a good one.
If it has been commercially rebuilt, it could be junk.
Look up Lars Grimsrud; he is one of the last Q-Jet gurus ans a great guy.
He will rebuild it for around $200 depending on parts needed.Lars
If your carb is junk, there are some decent options.
Holley makes a Q-Jet replacement.
I would try a Street Demon, which is an easy replacement.Street Demon
Good Luck. I love Q-Jets; I run a Lars rebuilt on my '68 L36.
Other rebuilders are Henry Olsen (local here in San Mateo, CA) and Cliff Ruggles.