Dip jr15

Hi I have a 1980 chevy k20 fleet side. It runs rough but will run better when it warms up. The truck will die when I go to a stop or put it in gear unless I got it high throttle. I'm putting in a new mechanical fuel pump and checking the timing. I'm curious if there is anything else I can do or should do to help fix this problem. I also need help on how to tune a two barrel carburetor. Thanks a lot!