Cooling System Questions

["Jim Hannon" <jhannon@domain.elided>]

IH Y'all,
  The P.O. of my '78 Scout lost a few pieces in the 4 years it sat in his
yard. One thing in particular is the coolant tubes the run from the pump to
the heads along with the retaining clips that hold them to the heads. Can
parts like this be bought at a Navistar dealership or do I needed to start
digging in the local junkyards. I would think that they would still carry
parts for the motors because of their wide use, but it has been a while. By
the way the motor is a rebuilt 345. I don't know if the tubes are different
between the 304 and 345. Any info is welcome.
Thanks,
Jim Hannon
'78 Scout II in need of TLC