I have done some more work and some additional testing. I have replaced all the line from the fuel tank to the front and added lift pump inline to help with fuel delivery. What i see now when scanning is a bit different but still under load the truck will not achieve desired rail pressure. If its in park and you rev it it can hit as high as 17k actual rail pressure. When under load will not go above 8k.
Also seems odd to me if i command 21k rail pressure the truck only hits about 8k. But if i rev it in park it has hit 17k seems odd to me.