Upgrade fuel pressure blue spring kit?
 

Will this work on the 7.3s or are the 6.0s the only ones that need it.
Tousley Ford Parts Depot

Not sure honestly, doesn't look anything like the return on my fuel bowl, I put on this kit with the black spring: Riffraff Diesel: Fuel Rail Crossover™

Check the fuel pressure... If its less then 50psi then mess with it...

Fuel pressure needs to be solid, but so long as its 50-70 psi, you will gain nothing.