73'- Early 74' will have the standard metal brackets
Late 74' to 76 will have shock bumper brackets
The late 74' to 76' have the outside mounting bolts spread out closer to the fenders than 73' to early 74' making them incompatible to swap
This has been confirmed on our Late build 74' Valiant and through comparing it against my 73' Duster bumper.
This is also evident by the fact that our early build 74 Swinger has the standard style mounting brackets
