Name this carb

Door Stop ? Just kidding. I cant remember but I do believe Holley..
I will guess that the carb is a 1971-77 ?
They ran very lean, dealership customers would complain about poor driveability .
There was a trick if you removed the tin cover there was a adjustable screw,maybe a allen screw that you would bottom out that would help with better driveability.
1977 was my last year at the dealership so I'm a bit foggy about it.