Gear oil (ATF) Level symptoms (Chevy)

Hello together, I’m starting again with a beginner question:How are the general symptoms for too much or too little transmission oil in the machine? Vehicle: Chevy Impala 1975 Station Wagon, engine: 350 SB (from a 1979 Camro Z28) Gearbox: TH400 Phenomenon: Putting in gear is wonderful with a little jerk (closeness of force). When giving gas, however, the vehicle moves forward only after some delay and also does not achieve really high performance values – at least not so like last year it’s interesting that I don’t need to change the “gas foot position” when starting up. Easy gas: doesn’t happen much; just stay on it: rolls on after a few seconds…It feels like the converter has to be filled and the power only arrives late on the rear wheels. Can this be technically so? Since I know little about the operation of automatic drives, I just ask so easily in the round… I have refilled before a few weeks by the way (2 liters), because he didn’t want to move at all. But the oil level is bad to read: light pink on metal… great combo I’m curious about your answers.