[Keven]

The engine i got dosent have the return line off from the cp3 no line bolt nothing is this a check valve like im finding duing a search or a restricted fitting cummins site says part #3957290 inj return check valve 112.00 is this needed or can it be just a banjo bolt and line when i search that number other ones come up that say there a restricted fitting for 10.00 this is where im getting confused thanks again . Keven

 

[Keven]

This is the line that goes too the bottom of the filter housing from cp3

 

[Keven]

Got it figured out m10x-6jic fittings and line made at farm store

 

[Fxsu]

This is the line that goes too the bottom of the filter housing from cp3

The valve on filter closes only when you disconnect the line from the fitting, just to prevent fuel dumping out everywhere. I removed on my engine and just use -6an fittings.