Lag can be no fuel or too much fuel, I would start with a larger air cleaner (it it my eyes or does that look tiny), compression test, some carb clean, sea foam, then change the plugs, check the wires, adjust the timing and tune the carb...
I had a few cars in here that guys thought ran good, but just got used to putting up with bogging, poor acceleration , and off idle response.
I normally start with a can of seafoam, hook it right to the vac port and rev her up a bit, hold the throttle till she starts to clear up while I am doing that I will spray some gumout carb clean through the carb to get all of that cleaned out (I seen before and after, that stuff cleans the **** out of your combustion chamber). Also check for intake leaks while doing this, just spray some cc around the gaskets and bases.
Then I do a kind of tune up, check fuel psi, change plugs (checking compression as I got), retime, adjust the carb, and add some gas line anti freeze to the tank.
With the exception of a couple carbs needing power valves (mostly from back firing, a lot of people dont know that you back fire a holley a couple times and you most likely need a power valve, lol (unless you have a protector kit, which I always install) and a gasket here and there, all the issues were cured, throttle response was back, and when they ask "what was it?" I always say "I don't know"...
This is all stuff you can do yourself, or a decent shop shouldnt charge you more than 2 hours to check compression, change plugs, check fuel psi, time, and tune... you can do the carb clean and sea foam your self...
https://www.youtube.com/watch?v=6OVIfkPpJ4Q
https://www.youtube.com/watch?v=UA_-SeJTAEU
I pour it into a container, rev to an rpm where it wont stall and stick the big vac line right into it, with the motor warm, it will smoke like a bastid..
