LCA Bushings and Other Bushings

[Ironracer]

The heim joint is a fixed swivel. In order for it to "deal with that" it would need to have a small bit of fore and aft. It does not. The LCA end of the swivel strut rod must travel in an arc. It has no choice since there are no bushings at the K frame.

That's an extremely valid question and now it has me second-guessing I'm thinking you're right that movement has to be transferred somewhere but is that bad for the bushings? I understand Delrin has a harder durometer rating than the poly, but will that make them tear up faster

 

[RustyRatRod]

What happens is that the heim joint allows for moving through an arc. When you install the adjustable strut rod you set the length at ride height and as 72nublu said you have to move the LCA up and down to insure there isn’t any binding. If there is, you have the rod the wrong length or something else.

The heim has to be installed so that the joint is verticals, and not parallel to the ground. IOW’s, the bolt that attaches the heim to the frame must be running left to right and not up and down. If you do that, the heim allows the strut rod to move through an arc without binding or pulling or pushing on the LCA.

And there is no way on God’s green earth that the LCA can come off the pin, even a skosh if the strut rod is installed correctly.

Like I said, even if I was going to use rubber LCA bushings I would still use adjustable strut rods.

Yeah, I knew they installed vertical like that. Ok then, I guess I didn't have a full understanding of how a heim joint works. Thank you drive through.

 

[Ironracer]

Yes. The "middle" of the arc would be the "longest" travel. Then going up with the control arm or down would effectively "shorten" the strut rod and that movement would have to be transferred "somewhere". The only place we have now is the LCA bushing. It may well be it's such a "small amount" of fore and aft movement that it doesn't matter. But an arc is an arc.

I dig everything you're saying, makes sense

 

[Ironracer]

Yeah, I knew they installed vertical like that. Ok then, I guess I didn't have a full understanding of how a heim joint works. Thank you drive through.

I'm glad you mentioned they come with instructions I'm sure I would have looked at it and seeing which way they needed to go but it's nice to know they actually tell you how to do something and obviously I would assume you'd want to count the threads on both sides equal or something

 

[RustyRatRod]

I dig everything you're saying, it's just if I cut a piece of wood 5 ft long to go across the bottom of a wall and try to lift it up to touch the top of that wall no matter what the difference is that piece of wood is going to be too short so it would have to be longer going diagonally showing my uneducated opinion the shortest length would be straight out

You get what I'm sayin. And I believe @yellow rose, but as small as my little mind is, I just do not understand how a heim joint can "do that".

 

[Ironracer]

You get what I'm sayin. And I believe @yellow rose, but as small as my little mind is, I just do not understand how a heim joint can "do that".

Maybe it's self canceling due to the rearward thrust on a lower control arm from the tire? Lol. I don't know, I imagine it would be enough to drive me crazy if I tried to figure it out cuz I honestly cannot figure that one out it does clearly seem to me that if you go through severe Jounce and rebound, the Arm wood get tugged around a little bit...

 

[RustyRatRod]

Maybe it's self canceling due to the rearward thrust on a lower control arm from the tire? Lol. I don't know, I imagine it would be enough to drive me crazy if I tried to figure it out cuz I honestly cannot figure that one out it does clearly seem to me that if you go through severe Jounce and rebound, the Arm wood get tugged around a little bit...

I know how to tell. Measure. But then I have to buy "all that stuff" and if it's "too much movement for me" then I'm stuck with it. Maybe one of these guys can splain it better to me.

 

[yellow rose]

I know how to tell. Measure. But then I have to buy "all that stuff" and if it's "too much movement for me" then I'm stuck with it. Maybe one of these guys can splain it better to me.

I should have taken a video of mine when I put it together. You can watch it go up and down and not move the LCA.

Actually I could jack the car up and then let the front down and make a video of that. You could at least see half the motion.

 

[Ironracer]

I know how to tell. Measure. But then I have to buy "all that stuff" and if it's "too much movement for me" then I'm stuck with it. Maybe one of these guys can splain it better to me.

Well the damn upper and lower control arms can't move too much up and down course that would depend on the weight on the car the diameter of your torsion bars some people do weird **** to their suspensions to limit the travel on them but I would think he couldn't be a whole hell of a lot then again when you're dealing with your alignment which is set up in degrees and that bottom ball joint has a direct effect on Caster, how much is too much? Any, i would think. But they handled killer for their time. My 66 satellite would run through some turns pretty good. And I guess it's all supposed to be an upgrade isn't it? But dammit now that bug is in my head...

 

[RustyRatRod]

I should have taken a video of mine when I put it together. You can watch it go up and down and not move the LCA.

Actually I could jack the car up and then let the front down and make a video of that. You could at least see half the motion.

I totally believe that, but my mind cannot grasp it. It keeps tellin me an arc is an arc. LOL

 

[RustyRatRod]

Well the damn upper and lower control arms can't move too much up and down course that would depend on the weight on the car the diameter of your torsion bars some people do weird **** to their suspensions to limit the travel on them but I would think he couldn't be a whole hell of a lot then again when you're dealing with your alignment which is set up in degrees and that bottom ball joint has a direct effect on Caster, how much is too much? Any, i would think. But they handled killer for their time. My 66 satellite would run through some turns pretty good. And I guess it's all supposed to be an upgrade isn't it? But dammit now that bug is in my head...

Sorry bout that. I didn't mean to ruin it for you. LOL I thought it was a valid question and still do....and I believe out yellow friend, I just cannot get my mind around it.

 

[Ironracer]

Sorry bout that. I didn't mean to ruin it for you. LOL I thought it was a valid question and still do....and I believe out yellow friend, I just cannot get my mind around it.

Honestly I can't either especially since the strut is that an angle that means as the lower control arm moves up or down it's even more severely affected than it would be if it was coming out at a 90 degree angle from the K member

 

[72bluNblu]

You must have not looked at my drawing. The connector is hooked to the strut rod. IF the strut rod PIVOT is not in line with the pin of the lca then there will be two different arcs. Too high the rod will move the lca BACK as it moves up and pull forward as it drops, too low and the opposite. To far in or out and different arcs also. The lca will move! You do understand the principle of a hinge, that’s the perfect geometric plane for the lower control arm. I’ve rotated my lca and the center of the strut rod pivot is slightly inside the k-frame hole. I can see why Chrysler used those rubber biscuits so I don’t like the adjustable struts because it’s center is to far out-off the lca pin centerline. I want all the arcs the same and I’ll figure out a way to make it look right to pass the tech guys, just simple geometry.
One other thing, it don’t matter how long each part is as long as the intersect. Strut can be 4’ and lca 1’ still a triangle.

I looked at your drawing, as difficult as it was to tell what anything was attached to and how.

There will ALWAYS be different arcs. If you attach an additional strut to the strut rod, even if it's parallel to the pivot pin, the end that is attached to the LCA is traveling in an arc that is perpendicular to the arc that the LCA is moving in. That's before you even consider how it will be attached to the strut, or that you'll be adding an additional load in the middle of the strut rod.

There is a reason why the original strut rod is at an angle. It's so that the arcs are not perpendicular to each other. The different lengths mean that the arc have a different radius, but, they overlap at an angle with lessens the effect of the movement. And when you consider the relatively small amount of travel, the issue you have with the adjustable struts is not a problem.

You can not like it all you want, but if you install a set of adjustable strut rods and adjust them to the proper length you'll find that there is no binding within the range of travel of the LCA. I have, and it's not there. The arcs overlap well enough for that distance that it isn't an issue. The factory used large rubber bushings because they couldn't change the length of the strut rod, and needed the fudge factor of the big rubber bushings to make up for having large tolerances on the suspension points.

There are a lot of different manufacturers that use a single leg LCA and strut rod arrangement. Mustangs use it, GM used it on a lot of stuff, even 2wd Toyota Tacoma's use it. They all use a strut rod at a similar angle to what's used in the Mopar suspension. None of that is by accident. Meanwhile, you won't find anything that uses a dual strut rod arrangement with the strut rods tethered together. Too many moving parts tracing out different arcs while they all move up and down at different rates.

If the strut rod is adjusted to "whatever" the right length is, I'm not understanding how the LCA can slide on the pin. Since the forces that "might" cause that are on the OUTSIDE of the LCA (the tire) and the bushing on the opposite end, I find it difficult to see it sliding on the pin when it has the strut there to hold it, unless there is something WRONG.

If the forces at work "somehow" destroy the poly bushings because of sliding on the pin, then certainly piles and piles of rubber bushings would also have been destroyed, since they are not as hard, and there is also much less surface area since the rubber bushings are much shorter.

At least, that's how it looks "to me". I don't have a dog in the fight on this other than deciding which parts will work best for ME. I am pretty sure after talking to Peter today what those will be.

Your thinking is absolutely correct Rob.

I thought the pin can't slide out because of its tight fit. If it can turn it can slide. If you lube it it can slide out even easier. Gotha

If you read my post above I said while foot braking the car it pushes the wheel back and in turn forces the arm against the K-member. When launching the pressure release causes the LCA to bounce back which was causing my wheels to bounce front when they came up. Look at the toe change in the video above when the wheels would come up.

This same movement can be seen if you foot brake the car in reverse. The arm moves away from the K-member. The space we measured is 3/8 -1/2 inch as stated above. You can move it back that far with a pry bar on the lift . the torsion bar clip stops the movement. Without the torsion bar in you can pry it off the pin. The arm pivots back on the rubber strut bushing.

I built a lot of mopars over the years and I will never again use anything but OEM style parts. The OEM LCA bushings don't rip if tightened in the factory ride height position. The pin is tightened in the center of the arm travel. You guys that jack them up like they are 4x4's better use poly bushings. LMFAO

Brought a barracuda home with poly and adjustable struts. I'll get some picks on the lift when it comes in. I finally took the car for a ride the car wonders at high speed. We are tearing all the aftermarket junk out and lowering the car to stock ride height. It is way to high for comfort and the poly junk and struts have to go. Yeah it has all the things you all are talking about. What a mess.

View attachment 1715739574

View attachment 1715739575

That's a lot of work to do because someone didn't dial in enough positive caster. But by all means, do a crap load of unnecessary work because you don't understand how the upgraded suspension works. Seems apt punishment for your continued and willful ignorance.

Here is my only point of "misinderstanding". The LCA travels up and down perpendicular to the LCA shaft center line. So, that means the strut rod end must travel in a arc, since it is fixed to the LCA end. This is the reason for the rubber bushings. To allow "just enough" fore and aft with the strut rod at the K frame where it installs in the bushings. So now we're talking about replacing the stock strut rods with a swivel (which I want to do).

So now we have installed a swivel strut rod totally FIXED on both ends, with no bushings. So, my question now is, WHERE is the fore and aft movement NOW? Since the strut rod now is totally fixed with no bushings, it has no way to allow that small bit of fore and aft movement going through the arc. I can only assume that small amount of fore and aft movement is transferred to "whatever" LCA bushing we use and that now the LCA has that same amount of fore and aft movement. RIGHT?

That's an extremely valid question and now it has me second-guessing I'm thinking you're right that movement has to be transferred somewhere but is that bad for the bushings? I understand Delrin has a harder durometer rating than the poly, but will that make them tear up faster

There are two different arcs, you guys are correct. The lengths are different, so they have different diameters too. But the strut rod and the LCA are not perpendicular, they're at an angle. So the strut rod doesn't just want to move the LCA forward and back, it pulls it in and out as well. These are all small components of movement though. The thing is that with the lengths of the strut rods, the length of the LCA's, and the amount of travel that they move in, the arcs don't diverge all that much. Not enough to be a problem.

And as I said before, the easiest way to see this is just to install everything. Install the LCA and strut rod, torsion bar, upper control arm and spindle. With that whole assembly together and the torsion bar adjuster plate and bolt removed, the suspension can be cycled up and down through its entire range of travel. Adjust the strut rod so the LCA is all the way forward against the poly (or delrin) LCA bushing. Then make small adjustments to the length of the strut rod until the LCA and suspension move up and down without binding. That's the process, and having done it a number of times with different components I can tell you that you can always get the suspension to move up and down without binding. Which means although there are different arcs, the angle they're at and their different radii mean that they overlap for the entire range of travel. Or at least well enough that it doesn't cause binding.

 

[RustyRatRod]

I looked at your drawing, as difficult as it was to tell what anything was attached to and how.

There will ALWAYS be different arcs. If you attach an additional strut to the strut rod, even if it's parallel to the pivot pin, the end that is attached to the LCA is traveling in an arc that is perpendicular to the arc that the LCA is moving in. That's before you even consider how it will be attached to the strut, or that you'll be adding an additional load in the middle of the strut rod.

There is a reason why the original strut rod is at an angle. It's so that the arcs are not perpendicular to each other. The different lengths mean that the arc have a different radius, but, they overlap at an angle with lessens the effect of the movement. And when you consider the relatively small amount of travel, the issue you have with the adjustable struts is not a problem.

You can not like it all you want, but if you install a set of adjustable strut rods and adjust them to the proper length you'll find that there is no binding within the range of travel of the LCA. I have, and it's not there. The arcs overlap well enough for that distance that it isn't an issue. The factory used large rubber bushings because they couldn't change the length of the strut rod, and needed the fudge factor of the big rubber bushings to make up for having large tolerances on the suspension points.

There are a lot of different manufacturers that use a single leg LCA and strut rod arrangement. Mustangs use it, GM used it on a lot of stuff, even 2wd Toyota Tacoma's use it. They all use a strut rod at a similar angle to what's used in the Mopar suspension. None of that is by accident. Meanwhile, you won't find anything that uses a dual strut rod arrangement with the strut rods tethered together. Too many moving parts tracing out different arcs while they all move up and down at different rates.



Your thinking is absolutely correct Rob.



That's a lot of work to do because someone didn't dial in enough positive caster. But by all means, do a crap load of unnecessary work because you don't understand how the upgraded suspension works. Seems apt punishment for your continued and willful ignorance.





There are two different arcs, you guys are correct. The lengths are different, so they have different diameters too. But the strut rod and the LCA are not perpendicular, they're at an angle. So the strut rod doesn't just want to move the LCA forward and back, it pulls it in and out as well. These are all small components of movement though. The thing is that with the lengths of the strut rods, the length of the LCA's, and the amount of travel that they move in, the arcs don't diverge all that much. Not enough to be a problem.

And as I said before, the easiest way to see this is just to install everything. Install the LCA and strut rod, torsion bar, upper control arm and spindle. With that whole assembly together and the torsion bar adjuster plate and bolt removed, the suspension can be cycled up and down through its entire range of travel. Adjust the strut rod so the LCA is all the way forward against the poly (or delrin) LCA bushing. Then make small adjustments to the length of the strut rod until the LCA and suspension move up and down without binding. That's the process, and having done it a number of times with different components I can tell you that you can always get the suspension to move up and down without binding. Which means although there are different arcs, the angle they're at and their different radii mean that they overlap for the entire range of travel. Or at least well enough that it doesn't cause binding.

View attachment 1715739628

Ok, cool. Then my suspicions were right. That while they might make things change "a little" it ain't squat enough to matter. I figure that had to be the case, or nobody would be selling crap that doesn't work. lol Thanks for the explanation.

 

[RustyRatRod]

View attachment 1715738799 View attachment 1715738800
This is for drag racing only, totally not not needed on street. Top uca bolts can move out of alignment, just look what holds the stock bushing, a thin ‘ring’. designed to move a little

Just a question if you don't mind. Does the allen head bolt that holds the washer on interfere with the front of the torsion bar hex? Did you have to drill a hole in the front of the torsion bar hex for the bolt to fit into?

 

[Oldmanmopar]

Ok, just so I’m clear on this. Are you saying you used poly LCA bushings and OE strut rods? Or did you use poly bushings and some brand of adjustable strut rod.

Just trying to understand what you are talking about. BTW, the sky IS blue. I don’t question you when you say something that makes sense.

Well I can't tell you how many cars come through here over the years that I have replaced poly suspension parts on that were installed including many cars from this site. My car which I only put over 800 miles on over 6 years had both. I have seen this with poly on both and rubber struts and torn OEM lowers.

I was heating the tires on the street with a wider radial up front and slicks on the rear. The front tires stuck to the road pretty good and the poly strut bushings squashed out and came out from under the car in pieces. Putting them in a big vice on the bench you can crumble them like butter. Rubber goes back to there original form.

We reinstalled another set of poly bushings and were putting the car up against the roll control while several watching with the hood open. With a remote filter and headers out the fender wells you could see the LCA's easy. That is when we noticed the Arms pulling away while on the brake in reverse and moving back front in 1st/low. you didn't even have to give it much throttle. Just go from forward to reverse with your foot on the brake.

We reinstalling another set of arms to eliminate the stabilizer tabs we used OEM rubber. This cured the problem. I found many liked the poly bushings because they are an easy install including myself until I saw this issue. When you have a big HP motor and pulling hard on the big end with the front end light from torque you really feel the steering move around with these after market parts. We have one here now we bought from a member.

I lost a car due to chinese junk after market parts failing. I will never use anything but OEM bushings and hardware on these cars. The brown Duster X drag car I just sold had 50 year old bushings when taken apart. The LCA bushings were still centered and not torn. Why change something that works is my point. I've done a lot of cars over the years . I really don't care who uses what. I am just stating what I have seen with my own eyes.

The you have Assholes like "blowjobblue' that state I am installing them wrong. Do they think we're putting them in backwards. LMAO. Believe me the strut rod does not hold the control arm front at the k-member unless there is force pushing the ball joint back with rearward force.

Remember this picture . Why do you think they had a shear sleeve added to the strut bushing. Does the poly bushing have this? No!
Not my first rodeo.

 

[Ceedawg]

Just a question if you don't mind. Does the allen head bolt that holds the washer on interfere with the front of the torsion bar hex? Did you have to drill a hole in the front of the torsion bar hex for the bolt to fit into?

Just lays in there and I space the bolt so it doesn’t tighten up. This is a race car that will see very few ‘miles’ so I’m not concerned about the wear issue. I’m thinking of putting the tie pice in and not having to use the bolt, that will be stronger anyway (constant rethinking) lol. I need a lot of travel for weight transfer since we’re limited to a 9” slick but on a street car (daily driver) with minimal travel the stock stuff suffices. As far as other makes of cars lower control arm, take a stroll thru the junk yards and see how many have a ONE piece unit, front or back. Chrysler used this design because it was cheap and somewhat efficient and would only see maybe 2” of up and down in normal driving. I checked again last nite, the pivot centerline for the strut in relation to the lca pin is about 1/2” in the hole where the rubber bushings go so they did get it close. The QA1 swivel is about 1-1/2” out so there arc is way out of line but would be ok with 2” of up and down street car movement. Street or race two different animals.

 

[yellow rose]

Well I can't tell you how many cars come through here over the years that I have replaced poly suspension parts on that were installed including many cars from this site. My car which I only put over 800 miles on over 6 years had both. I have seen this with poly on both and rubber struts and torn OEM lowers.

I was heating the tires on the street with a wider radial up front and slicks on the rear. The front tires stuck to the road pretty good and the poly strut bushings squashed out and came out from under the car in pieces. Putting them in a big vice on the bench you can crumble them like butter. Rubber goes back to there original form.

We reinstalled another set of poly bushings and were putting the car up against the roll control while several watching with the hood open. With a remote filter and headers out the fender wells you could see the LCA's easy. That is when we noticed the Arms pulling away while on the brake in reverse and moving back front in 1st/low. you didn't even have to give it much throttle. Just go from forward to reverse with your foot on the brake.

We reinstalling another set of arms to eliminate the stabilizer tabs we used OEM rubber. This cured the problem. I found many liked the poly bushings because they are an easy install including myself until I saw this issue. When you have a big HP motor and pulling hard on the big end with the front end light from torque you really feel the steering move around with these after market parts. We have one here now we bought from a member.

I lost a car due to chinese junk after market parts failing. I will never use anything but OEM bushings and hardware on these cars. The brown Duster X drag car I just sold had 50 year old bushings when taken apart. The LCA bushings were still centered and not torn. Why change something that works is my point. I've done a lot of cars over the years . I really don't care who uses what. I am just stating what I have seen with my own eyes.

The you have Assholes like "blowjobblue' that state I am installing them wrong. Do they think we're putting them in backwards. LMAO. Believe me the strut rod does not hold the control arm front at the k-member unless there is force pushing the ball joint back with rearward force.

Remember this picture . Why do you think they had a shear sleeve added to the strut bushing. Does the poly bushing have this? No!
Not my first rodeo.

View attachment 1715739660

View attachment 1715739668

View attachment 1715739669

View attachment 1715739671

View attachment 1715739672

View attachment 1715739673

So I read all this (twice) and you didn’t (or couldn’t) answer the simple question I asked. So I’ll ask one more time.

When you used poly LCA bushings did you use an adjustable strut rod?

That should be an easy one word answer. Yes or now.

 

[TheContractorDude]

This thread has been educating, learned a lot. Even got spicy lol. In the end we all share an appreciation for these beautiful cars. I was wondering if someone could point me in the right direction for sourcing the proforged greaseable bushing where I don't have to buy the whole frickin kit. Already called around and no one splits them up.

PST sources this out and the guy on the phone told me energy suspension supplies the bushing. However, I found they don't. Summit sells the kit for $99.00 so really no big deal. Cheap price for a mistake. Live and learn. Thanks again for all the input on this thread!

 

[Oldmanmopar]

So I read all this (twice) and you didn’t (or couldn’t) answer the simple question I asked. So I’ll ask one more time.

When you used poly LCA bushings did you use an adjustable strut rod?

That should be an easy one word answer. Yes or now.

They are on the barracuda pictured above the swivel on the front behind the bushing allows more movement . The poly strut bushings are the stiffest but the K-member hole shears off the flange that is suppose to hold them center. The rubber style wears but takes some time. The moog with the shear sleeve built in the bushing are the best. from the experience I have had with them on my cars and cars that come here for repairs I just have not seen any I would use again.
I tried all combos. Does it really matter . You'll find something incorrect. You and ******** blue always do.

 

[RustyRatRod]

They are on the barracuda pictured above the swivel on the front behind the bushing allows more movement . The poly strut bushings are the stiffest but the K-member hole shears off the flange that is suppose to hold them center. The rubber style wears but takes some time. The moog with the shear sleeve built in the bushing are the best. from the experience I have had with them on my cars and cars that come here for repairs I just have not seen any I would use again.
I tried all combos. Does it really matter . You'll find something incorrect. You and ******** blue always do.

All this name calling nonsense is uncalled for and really taking away from an otherwise informative thread.

You've still not answered the question, either. You said the Barracuda you have NOW has the adjustable strut rods. The question was if YOU used them in conjunction with poly LCA bushings.

It's my understanding when using swivel type adjustable strut rods, the bushings must be eliminated, so if that Barracuda has bushings in the strut rods, like you clearly said, then that's wrong.

I'll say it again. I don't have a dog in the hunt with this stupid dick measuring contest, but the insults and bullshit from either side aren't needed. This is a good thread where people can actually learn. Lets try our best to let it remain as such, ok? ALL of yall have good points to add without the bickering.

Lastly, with as MANY applications as have poly and delrin bushings running successfully in all forms of racing and on the street with NO failures, the ONE failure you speak of having had to be either bad parts or improper installation. There's just no other explanation. People aren't coming forward with tons of poly and delrin bushing failures. It's simply not a reality.

 

[yellow rose]

They are on the barracuda pictured above the swivel on the front behind the bushing allows more movement . The poly strut bushings are the stiffest but the K-member hole shears off the flange that is suppose to hold them center. The rubber style wears but takes some time. The moog with the shear sleeve built in the bushing are the best. from the experience I have had with them on my cars and cars that come here for repairs I just have not seen any I would use again.
I tried all combos. Does it really matter . You'll find something incorrect. You and ******** blue always do.

Way to not answer the question. I asked for a simple yes or no and you can’t do that.

 

[RustyRatRod]

Way to not answer the question. I asked for a simple yes or no and you can’t do that.

AM I right in my assertion that when using adjustable strut rods with a swivel that they should have no bushings of any kind? None of them I can find come with any. They only come with thick solid washers that act as solid bushings.

 

[yellow rose]

AM I right in my assertion that when using adjustable strut rods with a swivel that they should have no bushings of any kind? None of them I can find come with any. They only come with thick solid washers that act as solid bushings.

Right, no bushing, although there might be some adjustable strut rods with bushings that I haven’t seen. Ain’t no way I’d buy a set of adjustable strut rods with any kind of bushing on the heim end except the solid bushings like the QA1’s have.

EDIT: I just did a quick search and I see that PST and Mancini evidently have adjustable strut rods with poly bushings. I’m just not sure I like that. Even poly bushings will move and to me, the point of the adjustable strut rod is to get a solid link between the LCA and the frame.

 

[RustyRatRod]

Right, no bushing, although there might be some adjustable strut rods with bushings that I haven’t seen. Ain’t no way I’d buy a set of adjustable strut rods with any kind of bushing on the heim end except the solid bushings like the QA1’s have.

That's all I've seen so far. They have either steel or billet aluminum "biscuits" that replace the bushings making that front connection solid. Seems like a good upgrade "to me".