Suspension Bushing Mixing
Thread Starter
2nd Gear
Joined: Oct 2025
Posts: 2
Likes: 0
Suspension Bushing Mixing
Hello C4 owners! I have a question regarding suspension bushings.
I recently bought a 1995 M6 Coupe that, like most 30 year old cars, needs pretty much every functional piece of rubber replaced. I am planning a total suspension overhaul, and I need some help choosing the right bushings. From my research I am leaning towards Superpro bushings, but the full kits sold by various vendors like C&S Corvettes, Dino's Salvage etc are now non-existant since Superpro started selling their stuff directly here in the US. You can still get their bushings, but they don't seem to sell the full kit, meaning the total price for a complete replacement from them has gone up significantly.
My question is: Would there be any issues or drawbacks to using the stiffer bushings offered by Energy Suspension or Prothane (which can be had for quite a bit less money as a full kit) for most of the suspension and using the softer Superpro bushings in the rear where a softer bushing is needed (the dog bones I believe, correct me if I'm wrong) to support multiple axes of movement?
I have considered going to heim joints for those as well, but those parts aren't cheap either and I feel those are a bit too race-oriented for my current goals. It'll mostly be a street car. I would like to get into autocross when I've gotten it back into shape, but I think starting off relatively stock is the right way to go for someone inexperienced like me. I can always make that upgrade later if I feel it is necessary.
Thanks for your help!
I recently bought a 1995 M6 Coupe that, like most 30 year old cars, needs pretty much every functional piece of rubber replaced. I am planning a total suspension overhaul, and I need some help choosing the right bushings. From my research I am leaning towards Superpro bushings, but the full kits sold by various vendors like C&S Corvettes, Dino's Salvage etc are now non-existant since Superpro started selling their stuff directly here in the US. You can still get their bushings, but they don't seem to sell the full kit, meaning the total price for a complete replacement from them has gone up significantly.
My question is: Would there be any issues or drawbacks to using the stiffer bushings offered by Energy Suspension or Prothane (which can be had for quite a bit less money as a full kit) for most of the suspension and using the softer Superpro bushings in the rear where a softer bushing is needed (the dog bones I believe, correct me if I'm wrong) to support multiple axes of movement?
I have considered going to heim joints for those as well, but those parts aren't cheap either and I feel those are a bit too race-oriented for my current goals. It'll mostly be a street car. I would like to get into autocross when I've gotten it back into shape, but I think starting off relatively stock is the right way to go for someone inexperienced like me. I can always make that upgrade later if I feel it is necessary.
Thanks for your help!
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
Good question, and you're on the right track with your thinking about all of this. To answer your question up front: you can certainly mix and match bushings and even heim joints.
The two places where you really don't want stiff urethane or Delrin bushings in a C4 are the trailing arms (dog bones) and the rear lower lateral links (camber arms, strut rods). That's because both of those links arc in more than one plane, so they need to move around multiple axes. Super Pro or heim joints are a good way to go for these. You could consider doing threaded heim joints for just the strut rods: this would get rid of the factory eccentric rear camber adjusters (which slip and don't offer a big range of camber) and use the threaded joints to adjust camber instead. That would be beneficial for autocross or track use, but it's not a big deal for street use.
Every other bushing could be substituted with regular hard and cheap urethane. The one real downside is that they can sometimes be squeaky if they don't have good lube. I would encourage you to at least consider the offset Delrin bushings for the front lower control arms, as sold by After Dark Speed (and maybe Vansteel?). This would allow for more front negative camber, which again is very helpful for autocross or track use, but not important for street use. Delrin is also self-lubricating, so it's less likely to get squeaky, and it's stiffer than even hard poly.
The two places where you really don't want stiff urethane or Delrin bushings in a C4 are the trailing arms (dog bones) and the rear lower lateral links (camber arms, strut rods). That's because both of those links arc in more than one plane, so they need to move around multiple axes. Super Pro or heim joints are a good way to go for these. You could consider doing threaded heim joints for just the strut rods: this would get rid of the factory eccentric rear camber adjusters (which slip and don't offer a big range of camber) and use the threaded joints to adjust camber instead. That would be beneficial for autocross or track use, but it's not a big deal for street use.
Every other bushing could be substituted with regular hard and cheap urethane. The one real downside is that they can sometimes be squeaky if they don't have good lube. I would encourage you to at least consider the offset Delrin bushings for the front lower control arms, as sold by After Dark Speed (and maybe Vansteel?). This would allow for more front negative camber, which again is very helpful for autocross or track use, but not important for street use. Delrin is also self-lubricating, so it's less likely to get squeaky, and it's stiffer than even hard poly.
Thread Starter
2nd Gear
Joined: Oct 2025
Posts: 2
Likes: 0
Good question, and you're on the right track with your thinking about all of this. To answer your question up front: you can certainly mix and match bushings and even heim joints.
The two places where you really don't want stiff urethane or Delrin bushings in a C4 are the trailing arms (dog bones) and the rear lower lateral links (camber arms, strut rods). That's because both of those links arc in more than one plane, so they need to move around multiple axes. Super Pro or heim joints are a good way to go for these. You could consider doing threaded heim joints for just the strut rods: this would get rid of the factory eccentric rear camber adjusters (which slip and don't offer a big range of camber) and use the threaded joints to adjust camber instead. That would be beneficial for autocross or track use, but it's not a big deal for street use.
Every other bushing could be substituted with regular hard and cheap urethane. The one real downside is that they can sometimes be squeaky if they don't have good lube. I would encourage you to at least consider the offset Delrin bushings for the front lower control arms, as sold by After Dark Speed (and maybe Vansteel?). This would allow for more front negative camber, which again is very helpful for autocross or track use, but not important for street use. Delrin is also self-lubricating, so it's less likely to get squeaky, and it's stiffer than even hard poly.
The two places where you really don't want stiff urethane or Delrin bushings in a C4 are the trailing arms (dog bones) and the rear lower lateral links (camber arms, strut rods). That's because both of those links arc in more than one plane, so they need to move around multiple axes. Super Pro or heim joints are a good way to go for these. You could consider doing threaded heim joints for just the strut rods: this would get rid of the factory eccentric rear camber adjusters (which slip and don't offer a big range of camber) and use the threaded joints to adjust camber instead. That would be beneficial for autocross or track use, but it's not a big deal for street use.
Every other bushing could be substituted with regular hard and cheap urethane. The one real downside is that they can sometimes be squeaky if they don't have good lube. I would encourage you to at least consider the offset Delrin bushings for the front lower control arms, as sold by After Dark Speed (and maybe Vansteel?). This would allow for more front negative camber, which again is very helpful for autocross or track use, but not important for street use. Delrin is also self-lubricating, so it's less likely to get squeaky, and it's stiffer than even hard poly.
I've read TONS of threads here and on other forums about suspension upgrades on these cars. You'd think I'd have run across someone mentioning Delrin bushings before, but this is the first I've heard about them. I will certainly look into it. Thank you!
Instructor
Joined: Apr 2017
Posts: 156
Likes: 36
From: Cleveland Ohio
Superpro full kit is back in stock at C&S--ordered mine on Friday. The only things it doesn't include are sway bar and diff mount bushings but they're readily available. I went with poly for the sway bar bushings since I felt some stiffness was beneficial for that piece.
