[AndyP]

I have a 70ssLS5 Conv. that I am restoring. The original engine&tranny is gone so I'm going to go with the GM 454 crate and the richmond 5 SPD with 3:08 Rear (Thanks guys from a previous post!)

I was considering going with polygraphite bushings in the front and rear suspension, with KYB shocks because I want nice tight steering and handling but the main objective is some around town cruising, highway cruising and some traffic light to traffic light dragging. No track or organized racing.

Two people have now advised me against it as the convertible has a stiffer ride than the hardtop to start, adding poly would make it ride too hard as will the KYB's. They both said that someone who wants a nice cruiser should go with brand new OEM rubber, the original f41 components and premium Monroe Gas shocks would be best. What's your experience and thoughts?

 

[AndyP]

Forgot to add: I've already installed new OEM rubber body mounts. I'm refering to the front control arms, rear drag links both upper and lower, front and rear sway bar bushings and links and motor/tranny mounts.

Also what steering box is best, OEM or quick ratio?

 

[sanman]

I have a 70 rag top that i recently completed the entire suspension using PST poly graphite and KYB's. So far no complaints , However the car does ride firmer but that was expected due to the parts replaced were worn out. As far as the steer box, good question I also would like to know , I to need to replace mine.

 

[Kevin]

Hey Andy,

I have both a '71 SS convertible and coupe with poly everything, Guldstrand 600 lbs springs and KYB shocks. They both ride and cruise beautifully - even my 11 year-old daughter likes the ride. Go for it. I would like to know why your experts feel that the convertible has a stiffer ride. How can a convertible be stiffer than a coupe?

By all means get a newer/faster steering box - call Lee Manufacturing in Sun Valley, CA and you'll be set.

 

[von]

I put poly bushings in the rear susp of my '69 coupe. Wouldn't do it again. When crossing bumps the rear action is harsh. Reminds me of early Corvettes. If strictly for street use I would go with new rubber bushings. von

 

[drptop70ss]

I have the polygraphites in the rear of my car only, and have no complaints (big block conv)..I dont know how the convertible rides stiffer than the hardtop, had a lot of these cars and it really depends on your spring and
shock setup. I have nothing special gas shocks and factory springs, and if anything its a little too soft for me.

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70 chevelle ss396 conv
66 chevelle ss396 hdp/conv
55 chevy prostreet

 

[RT]

Andy, My '69 coupe has the full polyurethane treatment up front, KYB's all around. It handles great and the ride is firm. I like it. My '69 convertible has new OEM rubber in the front end, Monroe gas shocks, original bushings in the rear. It rides softer than the coupe, but I like it also because I didn't want a harsh ride in that car. But here's the funny thing; I did nothing with the sway bars on the convert.(standard front about 7/8" and none in the rear) and it takes turns almost as well as the coupe with 1-1/8" front and 1" rear Addco bars. The important thing I've noticed is the tires. If I switch tires from one car to the other, the handling will be very good on the car that has the BFG 60's and not as good on the one that uses the BFG 70's (these are a good bit older as well, so I'm sure it'll make a difference). I do feel the difference in ride harshness in either car when I switch tires, the 60's being the harder ride.
One more point, my convertible (maybe because it's a convertible) shakes in the cowl area on rough roads even with a new front end and new body bushings. I feel that this shake could be worse with poly bushings, but I have no proof.
Hope this helps you decide.
Rich

 

[Narti]

I have PST component's all around on my 70 SS 396 coupe, with gas shock's. I don't find the ride harsh at all!

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Nick P.
Team Chevelle Gold #36

 

[Clark]

Ive got poly bushings and KYB's on a 71 coupe and Its softer than I thought it would be. If you're used to modern cars the polys won't bother you at all. It feels firm but not harsh, It removed the "land yacht" feeling.

Just my opinion

Clark
TC #68

 

[von]

Hmmm. Maybe it's the tires on my car. I have stock springs, Monroe gas shocks, and no sway bar with the poly bushings on back. It has 60 series off brand on the back now. Going to BFG TA Radial 70 series this Spring. Maybe that will soften it up. von

 

[Pete 67]

I think depending on the area you live & the way you drive should determine the bushings & shocks you choose. In my Grand Prix(305 Chevy) I did the entire front end with polygraphite bushings & KYB shocks. I live in Long Island, & on the highways the car handled great, but was very very stiff. On the local streets the car was awful, the fillings in my teeth are still loose. I pulled the KYB's in a week & installed Monroe SensaTracs. Much better but still too stiff. This car is my daily driver so I guess I would like it smoother. If I did it again, I would stay with the rubber bushings. It all depends on personal preference.

 

[283v8]

Diffn't strokes for diffen't folks. If you want to simply cruise and enjoy a soft ride, go stock. If you want a "performance feel" and good cornering go PST. My 64 does not feel "harsh" with pst all around, but that is all relative. Heck, how many bumpy roads and railroad crossings will you be spending time on anyway????

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Gotta have a Chevy !In Durham N.C.
Why is there never enough time or money to do it right the first time, but ALWAYS enough to do it over?
Make it look the way you like it, forget what the other guys say!

 

[AndyP]

Thanks everyone, a certified toss-up!!! I think I'll try the OEM bushings and the premium monroe gas shocks to start and see how she goes. I will go with the quick ratio gearbox. Thanks again,

--Andy-- CT, USA

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1970 Chevelle SS Convertible
1937 Master Business Coupe
1996 S-10 Blazer

Yup, I'm Chevy Prejudiced!!!!

 

[Cardiac]

If you stiffen the ride with poly bushings you'll encounter body tweaking.
Poly bushings will not flex and will create wear spots resulting in squeeks. Unlike poly bushings, rubber will flex & has a memory therefore always returning to is original shape. Check with Global West www.globalwest.net their Del-A-Lum bushings are the way to go.
I like Koni shocks, spendy but worth it.

------------------
Lowered '67 Elcamino
ZZ430 eng / 4L60E trans
"Canyon Carver"

Susp: Neg. Roll

 

[RT]

Pete makes a good point. It won't help a person who does most of his driving on pot-holed city streets to get advice on ride harshness from someone who spends most of his or her time on the interstates. The same car will feel drastically different depending on where it spends most of it's time.
Rich