The HOSE NEW, NOT nos can be gotten from Cummins or any good truck shop, I would NOT use a nos hose because you do not know how old it is, could be from when the first 809 series was introduced, which means you could end up with the same issue or worse, being OLD nos means the hose will NOT be as flexible as it should be, it will tend to be hard, the inner sheath and wire could have deteriorated, the LAST thing you want to have either of those oil pump hoses BLOW OUT, the pressure side WILL pump ALL the oil OUT in about 30 sec (dead engine), if the suction hose gets a hole, the pump WILL suck air not oil, captivating the pump which will kill the pump and the engine.
So the BOTTOM LINE, BUY NEW hoses and when replacing one, REPLACE BOTH because both are most likely same age which means if one died then the other may be close, TWO NEW hoses may cost more then OLD nos, BUT still CHEAPER then installing another engine.