Fine Tuning using Scans

I have a good tune in my LBZ, and it has been great without issues until I replaced the turbo. I put in the stage 1 garrett and have had low boost under load. Especially while towing. I am also now getting a second or two of black smoke when I kick it down. The boost meets desired after a few seconds, but that isn't all that isn't right. I adjusted the Target Vane Position about 10% and it helped. But it was more of a shot in the dark, seeing the lag in the scans. My towing mileage dropped about 40% with the new turbo, which only tells me that it needs tuning adjustments. I would like to know how I can use the scans to adjust my tuning tables to better match. Is there a tutorial or how to out there that might explain how to do the fine tuning part?