1z engine with fiat croma diesel pump, injectors swap from Iveco Daily TD

Hi there,
I have a vw t3 van with a 1z engine conversion powered by a fiat croma mechanic diesel pump straight out of the box and intercooler, the engine runs but is very noisy (injector noise) and it does not produce enough power.
The mechanic that did the conversion has advised me that I need to replace the injectors he seams to remember that the injectors from the Iveco Daily TD are the best for the coma pump but he does not remember from which model (2.5td or 2.8td or???), does anyone here have any idea?
Many thanks
Luca

do you have a pic of the installed pump ? timing may be way advanced ... do you have any smoke on accelleration? i'm not sure about swapping injectors... alot has to be exactly the same beween the two injectors for it to work properly, spray angle being the first that comes to mind ....