2004 4 .6l gm motor

Hello there I have a 2004 4.6L mercruzee with a edelbrock 1409 on it and we had to change the fuel pump in it and I just can’t get it tuned right the 2 low ital srews are out 3 and 1/2 turn and the motor is set at about 600 6500 rpm and still kinda has a hard time starting and when it dose it blows black smoke and a little when u first step in it then clears up and when u are just sitting there u kinda can smell fuel just wondering what would be the best way to set the carb for this motor

Thanks huchters358