Bumper Help
It has exactly the right amount of holes for a standard mounting bracket frame rail. This is the front of the rail on one of my '71 Darts. Two threaded holes for the bumper bracket, two unthreaded holes that were likely some kind of factory use.
While I would never say it couldn't happen that a late '73 build got a shock bumper, I would be VERY surprised. I seriously doubt that ever happened. Regardless, the OP's frame rail is correct for a '73.
Your frame rail will not have the mounting hole and captured nut that was used for a shock bumper. Could you add it? Sure. It would be a lot of work to use the less desirable bumper though, because the mounting location is completely separate from the standard bumper mounting locations.
This is what I'm talking about. Here are the different versions of the frame rail, there are 3 I'm aware of (at least with regard to the bumper mounts). 67-73, which had the mounting holes for the standard brackets shown above, early model year '74 (August '73 until ~December) and then '75 on, and the wild card- mid to late '74 (~December to July).
The 1974 model year started production in August with shock mount front and rear bumpers. Those cars had only one bumper mount location, because the shock mount bumpers are mounted with a single bolt to the frame. And it's not in the same place as any of the standard bumper bracket mounts. You can see that on the picture below, showing a standard rail and either an early '74 rail or a 75+ rail.
Then, sometime around December of 1973 ('74 model year production), there was an issue with shock bumper production for the front, and starting from some time in December and on the remaining 1974 model year cars got standard bumpers again. But, they kept the shock bracket mounting hole. So, December '73 to July '74, model year 1974 cars had all 3 mounting locations. Like my '74 does.
But, your '73 will only have the standard bracket mounting locations, which you clearly show in your picture. Can you mount a shock bumper? Sure, but they're big, ugly, and heavy. And you'll either have to open up the frame rail to weld in a captured nut, or you'll have to drill a hole completely through the frame. Either that or you'll have to somehow modify the standard brackets to accept the shock mount style bumper. Which is probably easier than modifying the frame rail, but still. All just so you can run the wrong bumper on you car.
If you don't have any of the mounts I would just locate a set of standard bumper brackets and find a '73 bumper. It's going to be a lot easier than doing the work to run the wrong one, even if you have it already. Just my opinion.
It has exactly the right amount of holes for a standard mounting bracket frame rail. This is the front of the rail on one of my '71 Darts. Two threaded holes for the bumper bracket, two unthreaded holes that were likely some kind of factory use.
While I would never say it couldn't happen that a late '73 build got a shock bumper, I would be VERY surprised. I seriously doubt that ever happened. Regardless, the OP's frame rail is correct for a '73.
Your frame rail will not have the mounting hole and captured nut that was used for a shock bumper. Could you add it? Sure. It would be a lot of work to use the less desirable bumper though, because the mounting location is completely separate from the standard bumper mounting locations.
This is what I'm talking about. Here are the different versions of the frame rail, there are 3 I'm aware of (at least with regard to the bumper mounts). 67-73, which had the mounting holes for the standard brackets shown above, early model year '74 (August '73 until ~December) and then '75 on, and the wild card- mid to late '74 (~December to July).
The 1974 model year started production in August with shock mount front and rear bumpers. Those cars had only one bumper mount location, because the shock mount bumpers are mounted with a single bolt to the frame. And it's not in the same place as any of the standard bumper bracket mounts. You can see that on the picture below, showing a standard rail and either an early '74 rail or a 75+ rail.
Then, sometime around December of 1973 ('74 model year production), there was an issue with shock bumper production for the front, and starting from some time in December and on the remaining 1974 model year cars got standard bumpers again. But, they kept the shock bracket mounting hole. So, December '73 to July '74, model year 1974 cars had all 3 mounting locations. Like my '74 does.
But, your '73 will only have the standard bracket mounting locations, which you clearly show in your picture. Can you mount a shock bumper? Sure, but they're big, ugly, and heavy. And you'll either have to open up the frame rail to weld in a captured nut, or you'll have to drill a hole completely through the frame. Either that or you'll have to somehow modify the standard brackets to accept the shock mount style bumper. Which is probably easier than modifying the frame rail, but still. All just so you can run the wrong bumper on you car.
If you don't have any of the mounts I would just locate a set of standard bumper brackets and find a '73 bumper. It's going to be a lot easier than doing the work to run the wrong one, even if you have it already. Just my opinion.
