Why does my F-250 6.0 2007 truck have delay of power when I first take off,then it will pick up and go fine.

If you don't use full synthetic heavy duty diesel oil, it's only a matter of time until the turbo fails. Problems often start will a delay in turbo boost. Check for coking, bearing wear, and damaged blades.

Your turbo pobley needs the in side fins cleaned they sometimes get stuck