In general, a vacuum secondary carb is the most appropriate choice in a C-body. Nonetheless, that list 4777 Holley (650 mechanical secondary - "double pumper") can be made to work with respect to both performance and fuel economy.
The manual choke can be easily reinstated with an appropriate cable.
A renew kit and all the instructions are easily sourced.
Main difference between that carb and a Holley vac secondary 600 or 650 (apart from the secondary actuation method, of course) is the main system air/fuel ratio - the mech secondaries usually (but not always) run richer primary and secondary main systems. To improve matters, one can fit the mech secondary carb with the smaller jets of an equivalently sized vac sec. Jet sizes of stock Holleys are readily available online if you look under "HolleySpecs.pdf". Jets are easily sourced (my tip: buy genuine Holley ones thru Summit or Jegs etc).
Once reassembled with the smaller jets, the double pumper will match the vac secondary for economy if you drive it appropriately. The big advantage of the mechanical carb is that you will be able to feel the increased pedal resistance when the secondaries commence opening (correctly cited above as 40% - the percentage the primaries are open when the secondaries begin to open), and so it is easy to never open them if economy is the goal.
When, or if, you do need the extra power to pass a truck or Chevy, the pedal to the floor opens all 4 barrels instantly. This results in a significant torque increase over a vac secondary at any rev point until the vac secondaries are open fully. On some engines with the vac secondary spring set too heavy, the secondaries NEVER open fully at the rpm that engine can attain.
A 650 DP will work well on a 383 or a 440, and with some cheap jets a renew kit and choke cable, you'll be on the road for way less cash than another whole carb. Of course, if that 650 has a warped baseplate or bent throttle shaft or something equally serious, it'll be cheaper to buy that new (newer) vac secondary after all.
All the best!