300 sd doggey

I am working on a 1983 300sd, that seems to be way flat on the bottom end. Ran a compression test and came up at approx 310 -320 across the board, adjusted the valves. The engine starts super easy but it seems like the first 1/3 of the pedal does not do to much. Once the engine gets wound up it is ok but getting there takes some time. what do I need to do to make her somewhat responsive?