Challenger front bumper irons

[richardsmv6]

Is it possible to convert the 73-74 irons into the earlier ones? The reason being I have a load of spare later ones and need an early set for my 71? Will the bumpers still line up correctly?
Thanks

 

[challenger6pak]

What are you calling irons?

 

[richardsmv6]

What are you calling irons?

The 4 piece mounting brackets for the bumper