Some 3rd gens are just guttles from a dig.

I've done a lot of 3rd gen trucks from stock to large cam/turbo. Generally using the same transmission setting in most setups but some vehicles I get are just total turds down low. Don't hardly want to move from a dead stop or spin tires from a dig. Maybe something I'm missing or just some trucks move better than others. I tune a lot of vehicles MAF only Idk if this could have anything to do with it. This truck here is a stock 4x4 5.3 with mild cam but I've had lq4 trucks not want to move either. Maybe just bad cam/converter combo

Not tuning the VE is leaving power on the table. That MAF curve isn't very smooth either, it needs work.

Wrong cam choice will rob power down low if you run a stock stall converter.

Lower your PE enable settings, set the delay to 2,000 rpm, enable torque to 80% and use the MAP KPA to enable PE. That might help it take off better.