Need advice on my Holley DP 650

You dont need to remove the bowl to check the needle and seat. Just unscrew it and pull it up. When you re install it, go down further (leave about 3 threads showing above the bowl) then you think you need to. It’s easier to adjust the level up than down. To adjust it you have to have the fuel pump running, and the engine using fuel, to get the most accurate level.