Can anyone tell me what the application or difference is for these rear bumper reinforcements. I know it would be for a 73 or 74 Roadrunner or Satellite but they all have different part numbers on them. Can anyone give me more information regarding the numbers on them?

1) Part #3686605 39239
2) Part #3754255 39329
3) Part #3754273 39329

Thanks guys!

[img]https://s9.postimg.cc/6fbjxzfvv/48-2016-_Drag-_Weekend-_Best-_Burnouts-lpr.jpg[/img]


73 GTX *440*727*8 3/4*
69 DART GT *440*4 SPEED*DANA*
73 ROAD RUNNER *451*4 SPEED*DANA*
64 F100 *383*4 SPEED*9"*
75 DODGE D300 *440*4 SPEED*DANA*
99 DODGE RAM 3500 4X4 DUALLY... ON 38"s