fuel orifice 671 with N90 injectors

[stetson]

we have changed the fuel injectors on our lay down 671N to the N90 my question is should the restrictor orfice in the fuel return be a different size for this size injector? i know there are 3 different size orfice avalible for this particular engine.
thanks

 

[jgmo]

I have no reference for the in-line but my V 71N page lists 0.080" with a fuel spill of 0.9 gpm @ 1800 rpm. Fuel pressure 45-70. If your pressure and spill are good, then you have the correct orifice.