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Discussion Starter #1
68 fastback, 302

Need some suggestions. Going to replace either the coils or the shocks. Travelling over 70 miles the car wobbles a bit , after 100 miles on the highway - feels like the cars on waves.

What do ya all think change the shocks and coil springs ?

Also if changing the coil springs, is there much difference with the poly and rubber coil insulators ? I know the poly is about 10-15 dollars more.

Any suggestions would help. thanks
 

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sounds like you need new shocks to me
 

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Discussion Starter #4
If it feels like waves i would say you need shocks.


Forgot to mention .. when travelling high speeds, and the road has a slight wave, it bottoms out. Tires bottoming out with the fender lip. Im not sure if i should replace the coil and shocks ? or just shocks ?


So you guys think just shocks then ?
 

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Just my .02, but if you can do both, go for it, but at minimum shocks.
As to poly vs rubber: Rubber= softer feel, will degrade over time,
Poly= firmer, not subject to dry-rot, drying out, etc, but in some applications can make an annoying squeaking sound.

Hope it helps,
J
 

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If it bottoms out then you might need springs also. If you hit a bump and the car keeps bouncing after the bump then you need shocks. If it doesn't continue to bounce but bottoms out you probably need springs. The best thing would be to get both if you can afford it.
 

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Just because you're bottoming out on the fender lips doesn't necessarily mean you need new springs. What wheels and tires are you running and how far are they sticking out? If you like the stance of the car as it is you may just want to roll the fender lips. If the tires are sticking out too far for that you should think about getting a set of wheels and tires that fit.
 

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Discussion Starter #8
I got 255/60/15's on the rears , and 235 / 60/15'a on the front. Even when i use to have the 225/45/17's on the front they bottom out and suspension sways at high speeds as well. But the 235/60/15's are about a inch or 2 taller. No problems with the rears as i changed the leaf springs with the 1 inch lift.

My main concern is the handling though. Is the wavey feeling when travelling high speeds.
 

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The wavy feeling is probably because the shocks are bad. You shouldn't be rubbing with 225's or 235 if your wheels have the correct backspacing. Your old springs may be sagging a bit so a new set of springs might fix the rubbing or go with a higher spring rate but it sounds like you need some wheels with a higher backspacing to tuck into the fenders more. What backspacing do you have right now?
 

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Get a set of KYB Gas-a-Just shocks. They're not terribly stiff, but they're definitely an improvement over stock. They stop the suspension motion after one cycle and provide a fairly responsive ride. They're offered with most performance suspension kits. If you can, get springs too. Even stock replacement springs will make the car ride much better than it did. Your springs are probably heavily worn and lost much of their resistance.
 

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Discussion Starter #11
Its funny how you mentioned that to me. . i Just ordered a set of KYB gas-a-just shocks yesterday. Should be deleivered by next wednesday. I havn't ordered coil springs yet. . . still thinking ...
and the backspace is 15x8 magnum 500's , stock backspacing.
 

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As a quick guideline, the springs control the vehicle height and the shocks control the spring rebound. New shocks will not correct the bottoming out problem but they are likely to resolve the floating problem.
 

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Discussion Starter #13
oh ok.. so the wavey problem in high speeds the shocks should correct. The bottoming out problem happens when theres an instant dip in the road + high speeds. Yah, maybe i should get a pair of springs since i'll be replacing the shocks. I know theres 2 types the 620 lb, and 750 heavy duty ones. 620's should be ok right ?
 

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There are several different spring rates. I think the stock springs were something like 450-480. 620# springs are pretty stiff I wouldn't even think of using 750s. If you want a smooth ride I'd go with 540s.
 

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just one question when installing the front shocks are there for rubbers for the two bolts at the bottom cause when we got the kit they only came with two rubbers and if the only come with two rubber which side do they go on?
 
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