Maybe some of this is a repeat of other comments, but I'm typing it to make sure I articulate my meaning because I think there is an unanswered question on the bushings still.
The LCA pin is fixed into the subframe and tightened down - it does not pivot. Smear some type of lube for future disassembly purposes and rust prevention.
The LCA bushing is vulcanized to the inner and outer shells, which is then pressed into the LCA.
As the LCA is ~16" long (or whatever) the amount of suspension travel at the wheel requires only a few degrees of rotation at the bushing. So the outer bushing shell rotates with the LCA, the inner shell is stationary with the pivot pin, and the bushing gets squirmed to make it all happen. The overall design is such that the holding force of the rubber to the shells is sufficient that the rubber gets pulled but does not slip. OR it is all such a press-fit of rubber in the shells, with further pressfit when installed in the LCA, there there is no vulcanization, and the friction of the rubber on the shells performs the function.
So it would seem that a poly bushing is a totally different mechanism. From all the notes I saw years ago, the bushings stated that inner and outer shells needed to be re-used. So I suspect the bushing now functions as a bearing surface, and there is slip between bushings and shells. Certainly DIY people would not be able to assemble these bushings with the consistent pressfit (across all hobbyists) that OEM factory machinery would do in a production run, but slip-fit would certainly be a practical approach for DIY. And as it still has few degrees of rotation, the required lube is more for squeak prevention.
Other notes:
1. B-body strut rod bushings fit our cars. I have used a poly set in a car and I'm pleased with them. It really sucks how much disassembly is required to change them, the engineers should've made some type of drop-out feature for the front bushing setup.
2. B-body spring-eye and shackle bushings also work. There is a 1.5" and 2" OD for the front eye bushing, I believe the 1.5" is for Hemi cars, as the smaller bushing would give less squirm.
3. For our rear shackles, the poly bushings are
not a 100% fit, because the flanged surface is flat and not domed like the OEM rubber. However, I have used these with OEM shackles and not noticed any issues.
4. For the FirmFeel shackles - these can be readily be made at home with some suitable flat steel from
Mcmaster.com. (due to the small amount needed and online credit-card ordering, going to a steel house is likely not worth the few dollars saved.) I have made a set like this in the past - and no problems.
For all the shackle work - I used 9/16" bolts to fit the bushing IDs and then drilled shackle holes to match. Bolts with a long unthreaded section for the bushing to ride on would be elusive and pricey (they would be like shoulder bolts at that point). I used standard Grade5 or 8 bolts, so yes, some of the bushing is riding on the threads. Have not noticed any problems, and when I changed 1 set of OEM shackles with bolts/poly bushings to the heavier flat-steel shackles, the bushings were fine and I reused them. Those bushings surely had 50k miles on them, I put them in ~20 years ago.
