What are the suspension differences between 1966 Riviera GS and non-GS?

[C-Rad]

I recently purchased a tired 1967 Riviera.  It will be a weekend driver, but I want to generally keep it stock.  It's not a GS, but since I'm going to redo the suspension anyway (springs, bushings, joints (whatever wears out)) maybe I should replace springs and other parts with whatever enhanced parts the '67 GS had, rather than stock non-gs parts.  What were the specific differences in suspension?

Thanks

[RivNut]

There’s a really detailed article on the ROA’s website titled “How to ID a Gran Sport.”  All of these details are in that article.

[JZRIV]

Welcome to the forum.

 

GS coil springs had a slightly larger diameter wire size giving them a "slightly" stiffer rate, and it was only a few thousandths of an inch. There was no difference in ride height between GS (heavy duty) and non GS (standard). Only the spring rate changed. The 67 GS also had heavy duty shocks vs standard. Shock technology has changed a lot so trying to find something that mimicked the original heavy duty hydraulic shock is difficult.  Keep in mind the seat-of-the-pants feel between GS and non GS was minimal as this was still considered a luxury car to Buick and its buyer demographic. Soft and floaty was in and making it too rigid would scare away customers. Monroe made super duty shocks in the 70s into early 90s for these cars and I always felt these were superior to the standard gas shock that is available today. They had bigger bores and larger diameter rods which I felt was needed for the heavy car. Sometimes these show up NORS on ebay but not too often. Then complicating the aftermarket shock decisions for decades was it seemed the descriptive term "Heavy Duty" was used loosely by seemingly every aftermarket shock manufacturer to boost sales. Slapping that label on a shock didn't really mean much IMO

 

Use caution when replacing coil springs as many aftermarket springs will make the car sit too high. There are curb height specs in the shop manual. I'd check the height of your car and compare to spec before spending money on springs. Likely there are better places to spend money initially. 

There were no other differences in the GS vs non-GS suspension.

 

Money well spent is replacing front upper and lower control arm bushings, Front brake reaction rod bushings and stabilizer bar end links, Lower rear control arm bushings, and of course inspect ball joints. Of course this is dependent on a competent pre-inspection. Don't replace parts just to replace. Its possible the work has been done.

 

Its not relative to your question but the brake system should get top priority when preparing an old car for regular use.

Edited November 10, 2022 by JZRIV (see edit history)

[EmTee]

19 minutes ago, JZRIV said:

Of course this is dependent on a competent pre-inspection. Don't replace parts just to replace. Its possible the work has been done.

Also, consider that still serviceable components may be of higher quality than many of the replacements available today.

[1965rivgs]

2 hours ago, JZRIV said:

Welcome to the forum.

 

GS coil springs had a slightly larger diameter wire size giving them a "slightly" stiffer rate, and it was only a few thousandths of an inch. There was no difference in ride height between GS (heavy duty) and non GS (standard). Only the spring rate changed. The 67 GS also had heavy duty shocks vs standard. Shock technology has changed a lot so trying to find something that mimicked the original heavy duty hydraulic shock is difficult.  Keep in mind the seat-of-the-pants feel between GS and non GS was minimal as this was still considered a luxury car to Buick and its buyer demographic. Soft and floaty was in and making it too rigid would scare away customers. Monroe made super duty shocks in the 70s into early 90s for these cars and I always felt these were superior to the standard gas shock that is available today. They had bigger bores and larger diameter rods which I felt was needed for the heavy car. Sometimes these show up NORS on ebay but not too often. Then complicating the aftermarket shock decisions for decades was it seemed the descriptive term "Heavy Duty" was used loosely by seemingly every aftermarket shock manufacturer to boost sales. Slapping that label on a shock didn't really mean much IMO

 

Use caution when replacing coil springs as many aftermarket springs will make the car sit too high. There are curb height specs in the shop manual. I'd check the height of your car and compare to spec before spending money on springs. Likely there are better places to spend money initially. 

There were no other differences in the GS vs non-GS suspension.

 

Money well spent is replacing front upper and lower control arm bushings, Front brake reaction rod bushings and stabilizer bar end links, Lower rear control arm bushings, and of course inspect ball joints. Of course this is dependent on a competent pre-inspection. Don't replace parts just to replace. Its possible the work has been done.

 

Its not relative to your question but the brake system should get top priority when preparing an old car for regular use.

Jason,

  I believe the `66 GS also received the heavy duty track bar bushing as in the `65 H2 suspension.

Tom

 

  

[C-Rad]

Thanks very much for the detailed responses.  Brakes will be the first thing I go through, and tires (current ones are 15", but too small, I guess it was a cheap way to lower the car).  Then I'll address the front suspension (bushings, etc.).  I figure if I'm going to remove the front A-arms to replace the bushings, I will need to compress and remove the front springs anyway, and having new ones to put it at that time (if I need them) will be easier than having to remove them again. 

 

Is a lower ride the only indicator of worn out springs, or do old springs have any other symptoms?

 

What do most of you guys do for appropriate shocks?  (function, not looks)  There must be some modern shock that performs appropriately for an old heavy riviera.

 

Thanks again 

[EmTee]

5 hours ago, C-Rad said:

Is a lower ride the only indicator of worn out springs, or do old springs have any other symptoms?

Assuming there are no broken coils, ride height is the only performance specification that can reasonably be measured.