Riser block rear suspension???

[440 Smokin]

74 Cuda with a 440 and Tremec 5 speed. The car rides like a log wagon, especially the rear. Almost no give when you try to bounce the rear of the car. It has 6 leaf springs and for some reason an 1 3/4" riser block between the leaf springs and the axle bracket. KYB 554285 shocks. Not sure what the purpose of the riser is. Stiffen the suspension? Lower the stance? Rumor is it used to be a drag car, there are a couple of Mopar National window stickers on the front window.

So I want the car to ride better, more give in rear end. Willing to replace the springs and shocks. Maybe a premium adjustable shock like a QA1. Remove the risers? I like the stance of the car but would really like to get a decent ride and not have to inch over speed bumps anymore.

Any thoughts?

Thanks........

 

[cuda joe]

those blocks lower the rear of the car . i would unbolt the shock and measure the distance between the upper and lower shock mounts we will call the ride height .. then measure the shock fully compressed and fully extended the ride height should be between the 2 measurements of the shock .. if the ride height is to close to either the compressed or extended measurement of the shock the shock is bottoming out and it will ride like it has square wheels

 

[Chryco Psycho]

Removing the block will not change the ride at all .
You may have SS springs if it is sitting too high without the blocks ,
I would try better shocks first , double adjustable work best .
If it still is not what you want you can order different springs , the rear of the spring controls the ride , the front controls traction so you want as many as possible in front using 1/2 leafs .

 

[Xcudame]

Kinda sounds like you have SS springs. Get rid of the blocks! They probably ran a tall tire 29" or 30" diameter slick and wanted to lower the rear and added the blocks. Might be better off with these, the extra heavy duty 426/440 springs: P4452984 right and P4452985 left. They use 1/2 springs in the front. Unfortunately the right one is on backorder. Looks like maybe the end of July they might be back available.

Definitely go with the QA1 (or Bilstein) shocks! KYBs were cool when they first came out because they were better than factory or factory replacements, but there's better shocks available now.

 

[HPP]

When the axle is under the springs, that is a riser block because it will lift the vehicle. When the axle is over the springs, as in our cars, it is a lowering block. This black has nothing to do with ride quality unless it lowers the car so far the axle tubes are hitting the bump stops. At 1.75", I sincerely doubt that is the problem. If you remove them, the rear will be 1.75" higher. If you raise the front end 1.25" to 1.5", the whole car will sit higher with a slight rake, eliminating the need to go slow over bumps. So this may be an option to consider, but it has nothing to do with ride quality.

I'm also of the opinion that a 6 leaf spring pack is the equivalent of the factory HD suspension and should not be overly stiff and you should be able to push the rear down some amount, unless you only weigh 110#. Heck 318 and 225 cars had four leaf packs, so your only up a couple leaves from the lightest weight option. I doubt the leaf count is a problem because in your picture, I only see 4 full leaves. I'll assume the extra two are half leaves. You car should ride pretty decent.

KYB shocks are high pressure, divergent valved shock that create a very high initial resistance that will slowly give way with increased load. More load than you can get by just pushing on the car with. In any case, this high initial resistance is where small bumps and road cracks move the shock, the KYB will be putting up its highest resistance and creating a potentially rough ride. It's only when rapidly throwing it into corners that the KYBs work well because they slow the suspension reaction down significantly on the initial compression.

I'd recommend removing the shocks and then pushing on it to see if that allows the motion to free up. If yes, then the shocks are the problem. Is it the shock valving or the shock travel...that depends. With the car on the ground, and a large bar clamp, you can try compressing the shock to see if it allows enough travel to match the suspension. Even with lowering blocks, there should be adequate travel between the springs and shocks, but you never know until you check. If you had high arch springs, like Super Stock, then it could be possible you are running out of shock travel.

Out of curiosity, are there any additional clamps on the springs anywhere along their length? If this is indeed a former race car, they may have added extra clamps to help with launch.