Rubber strut rod bushings?
The K7040 strut rod bushings aren't suitable for the 73+ strut rods, certainly not without modifications. The inner diameter of the K7040's is 5/8", where the K7068's for the 73+ struts is 3/4" because of the inner sleeve that was used. The overall thickness of the bushing is also different, the K7040's aren't nearly as thick as the K7068's. So, they wouldn't slide over the 73+ struts using the later 73+ sleeve the way they're supposed to, and even if you left out the sleeve to get them on there you'd have to figure out a way to take up the leftover space (the K7040's do have an internally molded sleeve). If you just slapped the K7040's on there without the later inner sleeve and tightened the nuts down you would probably end up running out of threads before the bushings were properly compressed, leaving the strut rod loose. If you managed to get the bushings compressed, you would have pulled the LCA forward.
Ironically, these pictures are from @Oldmanmopar , showing the significant differences in the 73+ struts. The notations are mine to make things more clear
It should be obvious from the top picture that using the bushings intended for the 67-72 on the 73+ struts is a bad idea. Here's the original post where OMM basically said using the 7040 strut rod bushings on the later 73+ bushings is a bad idea. And for once regarding strut rods, he's actually right about that. Not sure why he changed his mind, he was right the first time. If you wanted to use the K7040 rubber bushings, you'd have to get a set of 67-72 strut rods. The 73+ strut rod set up is the better one, which is why it was redesigned from 67-72. And they made a lot more 73+ cars, so, I'm not sure why Moog has decided to discontinue that later bushing. It was better all the way around.
Some strut bushing info
As for the poly bushings, @autoxcuda ran them successfully for years. You can see what he did to modify his poly strut rod bushings so that they fit his car correctly. These were poly bushing he cut down in a lathe to fit the strut rods properly, he eventually replaced them with adjustable strut rods. I don't know what year strut rod he used originally, although there's more information in this thread. The issue is that the poly strut rods are all advertised as 67-76, and as you can see from the strut rod differences they can't accurately fit that entire range of original strut rods. They'd either have to be wrong for the 67-72 struts or the 73-76 struts, or, possibly the entire range. The ones I have seen looked like they were intended for the later 73+ strut rods, so they would have to be cut down for 67-72.
Here's that thread Cutting strut rod bushings for correct geometry?
The K7040 strut rod bushings aren't suitable for the 73+ strut rods, certainly not without modifications. The inner diameter of the K7040's is 5/8", where the K7068's for the 73+ struts is 3/4" because of the inner sleeve that was used. The overall thickness of the bushing is also different, the K7040's aren't nearly as thick as the K7068's. So, they wouldn't slide over the 73+ struts using the later 73+ sleeve the way they're supposed to, and even if you left out the sleeve to get them on there you'd have to figure out a way to take up the leftover space (the K7040's do have an internally molded sleeve). If you just slapped the K7040's on there without the later inner sleeve and tightened the nuts down you would probably end up running out of threads before the bushings were properly compressed, leaving the strut rod loose. If you managed to get the bushings compressed, you would have pulled the LCA forward.
Ironically, these pictures are from @Oldmanmopar , showing the significant differences in the 73+ struts. The notations are mine to make things more clear
It should be obvious from the top picture that using the bushings intended for the 67-72 on the 73+ struts is a bad idea. Here's the original post where OMM basically said using the 7040 strut rod bushings on the later 73+ bushings is a bad idea. And for once regarding strut rods, he's actually right about that. Not sure why he changed his mind, he was right the first time. If you wanted to use the K7040 rubber bushings, you'd have to get a set of 67-72 strut rods. The 73+ strut rod set up is the better one, which is why it was redesigned from 67-72. And they made a lot more 73+ cars, so, I'm not sure why Moog has decided to discontinue that later bushing. It was better all the way around.
Some strut bushing info
One thing you have to do when using this #PN is get 67-72 strut rods. These bushings #PN k7040 are for 67-72. The fine thread strut rods are much better then the coarse thread and will be the correct length, Don't ruin them drilling them for the longer 73 rods. You'll be buying new bushings. these are the best you can get
As for the poly bushings, @autoxcuda ran them successfully for years. You can see what he did to modify his poly strut rod bushings so that they fit his car correctly. These were poly bushing he cut down in a lathe to fit the strut rods properly, he eventually replaced them with adjustable strut rods. I don't know what year strut rod he used originally, although there's more information in this thread. The issue is that the poly strut rods are all advertised as 67-76, and as you can see from the strut rod differences they can't accurately fit that entire range of original strut rods. They'd either have to be wrong for the 67-72 struts or the 73-76 struts, or, possibly the entire range. The ones I have seen looked like they were intended for the later 73+ strut rods, so they would have to be cut down for 67-72.
Here's that thread Cutting strut rod bushings for correct geometry?