Longer Shocks

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Staffords

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I'm looking for longer shocks to work with Superstock springs and not finding alot of options. So far I've found the Mopar Performance shocks and the Competition Engineering extended drag racing shocks. This car will be a street driven hot rod so I'm leaning away from the Competition Engineering shocks as they are listed as "drag race only." I purchased these extended KYB Gas-a-Just shocks from Mancini Racing KYB Gas-a-Just Shock - Rear S/S Springs and the top eyelet mount is too small, even though it's advertised for A-bodys. Did I get the wrong shocks or does everybody just replace that top bushing on these? Wasn't sure if I can press out the bushing and replace it with one that fits without damaging the shock. If so, what bushing does it take?

If you have a shock that you know works, please provide the link or part number. Internet searches have not been very helpful as most online vendors sell the shocks by specific vehicle fitment and don't list the bushing/eyelet size or the extended/compressed lengths for the shock. I don't want to keep ordering parts that don't fit.
 
I purchased these extended KYB Gas-a-Just shocks
I wouldn’t buy KYB shocks, they’re horrible riding shocks. You can buy shocks by the size that you need, you’ll have to know the measurements. Do you have your old shocks that you can take measurements from? My preferred brand would be the Bilstein shocks, in my opinion.
 
Rancho 9-way single adjustable hocks have been used in rear drag racing applications. I had them on my Dart Sport for years but don't have the car here to confirm my particular #. Advertised applications include early Dodge pick-ups.

Link is to their master catalog.

* Usable part #'s at the bottom of page 179

* Mounting end styles are shown on page 164. Ours is L type - L type

* Measurements of individual mounting ends is on page 171. Ours is L1.


https://www.gorancho.com/cdn/shop/files/RanchoCatalogFull2022.pdf?v=6930269045184371590
 

The trick used to be to get some rear shocks for a C body, but over time, it appears the industry has homologated all the mopar shocks to the one part number for A bodies, which is not correct, of course. Those cars have not been made in so long, those original numbers are simply not made anymore. The extended length was right around 2" longer than the A body part numbers, so they were perfect. The KYB C body numbers now show only about a 1" difference in extended length and that's not enough.
 
Rancho 9-way single adjustable hocks have been used in rear drag racing applications. I had them on my Dart Sport for years but don't have the car here to confirm my particular #. Advertised applications include early Dodge pick-ups.

Link is to their master catalog.

* Usable part #'s at the bottom of page 179

* Mounting end styles are shown on page 164. Ours is L type - L type

* Measurements of individual mounting ends is on page 171. Ours is L1.


https://www.gorancho.com/cdn/shop/files/RanchoCatalogFull2022.pdf?v=6930269045184371590
Thanks, Myron! That's good info!
 
In my 72 Demon with SS springs (Mopar units I bought from the dealer) I ran stock shocks I believe are Monroe’s gas matics with no issues. Not even topping out (bottom out but for extension)
I wonder if you measure yours and get all the dimensions needed you can just call your favorite shock company and have them tell you what is available. The box auto part stores are useless.
Catalogs are also useless if what above is being said is correct about combining to save inventory space.

If we can get some good info, this would be a great place to keep this thread for future reference.
Syleng1
 
In my 72 Demon with SS springs (Mopar units I bought from the dealer) I ran stock shocks I believe are Monroe’s gas matics with no issues. Not even topping out (bottom out but for extension)
I wonder if you measure yours and get all the dimensions needed you can just call your favorite shock company and have them tell you what is available. The box auto part stores are useless.
Catalogs are also useless if what above is being said is correct about combining to save inventory space.

If we can get some good info, this would be a great place to keep this thread for future reference.
Syleng1
back in the day , Mopar recommended the imperial rear shocks for the s.s. springs , I acquired a pair , changed the bushings to work on my 68 fastback , then stumbled on to a caltrac set up for cheap and never used them , they are longer , we used to run them on the hemi car with 002-003 springs...
 
the imperial rear shocks
FWIW.....A vs C shock lengths
1755265234410.png
 
back in the day , Mopar recommended the imperial rear shocks for the s.s. springs , I acquired a pair , changed the bushings to work on my 68 fastback , then stumbled on to a caltrac set up for cheap and never used them , they are longer , we used to run them on the hemi car with 002-003 springs...
While the old Mopar Race Manuals had a lot of good info and still do, some of it has become obsolete. I found that the harder a car "hits" the suspension, the stiffer the shocks need to be. HP, converters, gears & tire technology have changed a lot. My 360 Dart Sport with SS springs running mid-low 11's didn't hook as well and even wheel-hopped under certain conditions with Competition Engineering adjustable shocks as well as with the Mopar recommended 4-speed drag shocks. The shocks couldn't control the separation and springs wrapping and un-wrapping. The stiffer Ranchos made a big difference.
 
Rancho 9-way single adjustable hocks have been used in rear drag racing applications. I had them on my Dart Sport for years but don't have the car here to confirm my particular #. Advertised applications include early Dodge pick-ups.

Link is to their master catalog.

* Usable part #'s at the bottom of page 179

* Mounting end styles are shown on page 164. Ours is L type - L type

* Measurements of individual mounting ends is on page 171. Ours is L1.


https://www.gorancho.com/cdn/shop/files/RanchoCatalogFull2022.pdf?v=6930269045184371590
I had Rancho shocks on an old CJ5 years ago, didn't think to look at an offroad shock. Thank you for the master catalog link and the page numbers provided. Extremely helpful.

After lots cross referencing and checking compatibility and google searches to for details I've found a pair of Bilstein 5125 shocks that have both the 5/8" eye top/bottom and the correct length, but who knows as far as valving goes. I'll report back if they work out.
 
So it turns out the rear shock studs (both upper and lower) on my car are 11/16" or 0.688" not 5/8. I don't know what they should be from the factory, but that's what I've got. It appears 11/16" is sort of an oddball size. Skyjacker and Energy suspension both claim to sell 11/16 ID polyurethane shock bushings, and both were actually 3/4" ID when they arrived. Google searches were not helpful in finding vehicles with 11/16" diameter shock studs.

I ended up ordering 5/8" ID Prothane polyurethane bushings and boring them out to 11/16ID on my lathe.

The rear shocks I settled on were a pair of Skyjacker M9527. They are 24.9" Extended and 14.9" compressed, the right length to work with my superstock rear springs. I was going to use Bilstein 5125 shocks (the Skyjackers are actually supposed to be a copy of the 5125s) but in comparing them side by side the Skyjackers were a bit firmer.

Got it all together and took it for a short test drive today. Feels a little firmer, but not harsh. Here's the before and after:

20250804_184746.jpg


20250827_190114.jpg


20250827_190205.jpg
 
I really like the QA1 shocks. they come in fixed, single adjustable and double adjustable. The range of adjustments goes from soft to very firm. I run mine on the second from the softest setting front and rear. Very good quality shocks.

My '70 'Cuda has a stick and a stroker motor. Controlling the body separation on the hit was an issue, I ended up getting a pair of AFCO double adjustable with their Big Dog valving. It's the only shock I've found that controls the separation on launch.

When I measured the eye to eye length with the shocks removed and the rear end sagging while the body was up on jack stands, I found I needed about an additional 2 inches in length over stock. I'm running a pair of 3200lbs driver's side springs with inset hangers. I control the spring wrap with a set of properly adjusted slapper bars. This set-up is the best I've found in the last 40+ years of experimenting.


IMG_2605.JPG
 
I really like the QA1 shocks. they come in fixed, single adjustable and double adjustable. The range of adjustments goes from soft to very firm. I run mine on the second from the softest setting front and rear. Very good quality shocks.
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My '70 'Cuda has a stick and a stroker motor. Controlling the body separation on the hit was an issue, I ended up getting a pair of AFCO double adjustable with their Big Dog valving. It's the only shock I've found that controls the separation on launch.

When I measured the eye to eye length with the shocks removed and the rear end sagging while the body was up on jack stands, I found I needed about an additional 2 inches in length over stock. I'm running a pair of 3200lbs driver's side springs with inset hangers. I control the spring wrap with a set of properly adjusted slapper bars. This set-up is the best I've found in the last 40+ years of experimenting.


View attachment 1716447704
The stance on that '70 Cuda looks killer!

I did look at the QA1 shocks and I've heard they're a high quality product but they don't appear to offer different lengths... QA1 shocks are all 23.6" extended, I was looking for something around 25" based on 2-2.5" longer than stock. Its only about 1.5" of difference and may have been absolutely fine but I was worried they would be in danger of topping out on extension during a hard launch with the 02/03 Superstock springs.
 
The stance on that '70 Cuda looks killer!

I did look at the QA1 shocks and I've heard they're a high quality product but they don't appear to offer different lengths... QA1 shocks are all 23.6" extended, I was looking for something around 25" based on 2-2.5" longer than stock. Its only about 1.5" of difference and may have been absolutely fine but I was worried they would be in danger of topping out on extension during a hard launch with the 02/03 Superstock springs.
For the longer length shock in the rear of my E-Body, I switched to AFCO. This was on a stick car with a stroked RB. On launch, the rear tires were hooking for a split second and then jumping off the ground when the body separation happened.

I sent them in to AFCO. After I explained what was happening, they advised me to have the valving made stiffer on the extension stroke. I also verified that the suspension travel on compression allowed enough stroke without bottoming.

I'm running the single adjustable QA1's on my '68 A-Body and on the front of my 1970, and love them. I have previously tried Bilsteins and Koni's, but prefer the QA1's.
 
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I'm looking for longer shocks to work with Superstock springs and not finding alot of options. So far I've found the Mopar Performance shocks and the Competition Engineering extended drag racing shocks. This car will be a street driven hot rod so I'm leaning away from the Competition Engineering shocks as they are listed as "drag race only." I purchased these extended KYB Gas-a-Just shocks from Mancini Racing KYB Gas-a-Just Shock - Rear S/S Springs and the top eyelet mount is too small, even though it's advertised for A-bodys. Did I get the wrong shocks or does everybody just replace that top bushing on these? Wasn't sure if I can press out the bushing and replace it with one that fits without damaging the shock. If so, what bushing does it take?

If you have a shock that you know works, please provide the link or part number. Internet searches have not been very helpful as most online vendors sell the shocks by specific vehicle fitment and don't list the bushing/eyelet size or the extended/compressed lengths for the shock. I don't want to keep ordering parts that don't fit.
I had the same problem with my rear shocks. Suspension was not allowed its full travel because of the shocks listed for my car. My fix for it was a pair of front shocks from a 2003 Ram 1500 rear wheel drive. I cut the studs off the pick up truck shocks and eyelets off the rear shocks of my Duster. The eyes were welded to the new shocks. Gives you about 4 inches of additional spring travel. I also have Super Stock springs in my Duster.
 
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