The Cooper-Jarrett Truck Trailers Car No. 6430 was produced from 1956 until 1958. Early issues would use Mold 6511-2, and have bar-end trucks with coupler tabs, while later issues would have AAR trucks with disc couplers. There are three variations:

Variation A: GRAY trailers with ALUMINUM "COOPER-JARRETT" signs.
Variation B: WHITE trailers with BLACKENED ALUMINUM "COOPER-JARRETT" signs.
Variation C: Same as Variation A or B but with AAR trucks. On these, the number moves to the left of the "LIONEL" inscription on the side of the flat car.