I know Service part ID's Z51 and Z52 but...

[KLUTZ]

What is this Z31 on my '87's build sheet? Is that the stock suspension ID#? I can't find it listed anywhere.

 

[boomdriver]

I believe thats base suspension. In 87 there was not a true "Z51". It was offered as Z-52 that was a little bit softer spring version of earlier HD performance suspension packages. The packages were made up of various sway bar types (solid, tubular)and sizes (thickness), shocks, springs (composite mono-springs) and bushing size/diameter and rack & pinion steering ratio..

Once upon a time I had the complete GM option list...about 30 pages worth that the CAC in Bowling Green faxed to me. I remember when I spoke to someone there and ask if they could send me something that explained all the options, they replied, "sure, all of them"? The factory support and owner assistance for Corvette has always been outstanding..if a single word were to be used. There is still an 800 # to call for q&a and help. They maintain 10 yrs back, then the data/records goe to storage and the archives. They can tell you who assembled your car, what shift, time of day it rolled off and where it went for first sale. They protect previous owner info and yours. If its a Corvette, they have records for it like it were a person.
I did'nt think anything about what I though was a simple document....until the fax started rolling off page after page...for the next 1/2 hour! Wish I knew where that was right now...still got it.....somewhere.

A couple things to look for.
Bilsteins shocks are yellow and will be an indication of an upgraded suspension package. Look at the sway bar ends to see if they are tubes or solid big bars. The steering wheel number of turns from lock to lock also indicates a sport, performance or base suspension. 3/4 to 1 turn each way is performance.
1 to 1.5 is sport,.(z52) and over 1.5 each way is base. Its not exact, but gives you an idea. Mine for example only makes 3/4 turn each way before bottoming out. A good sneeze changes lanes. Its sensitive. Others with a Z51 say theirs makes 1 full turn each way.

 

[KLUTZ]

Well, that answers that.

Thanks

 

[boomdriver]

'87 had Z51 "Perf handling" option ( I own one ) just like other years
and was the 1st year the softer Z52 "sports handling" pkg was available

1596 RPO Z51 produced in '87
12662 RPO Z52 produced

Interesting...
I was told by someone in Kentucky that the '51 was replaced by the '52 for a yr or two but was basically the same thing with a softer /slower spring rate. All that was needed to be the full on Z51 was the hardest spring that you could tolerate....which I did install, regretably...
Mine is labeled Z52, but has the fast rack, big solid sway bars, 'steins and everything else. Now it has a 499 lb/in spring that easily qualifies it as Z51.....(buckboard)

I miss my old 230 lb spring.....:duh

I had never heard that the "Z" code also covered trim packages....I always assumed it was strictly suspension package code.

 

[Hib Halverson]

Interesting...
I was told by someone in Kentucky that the '51 was replaced by the '52 for a yr or two but was basically the same thing with a softer /slower spring rate. All that was needed to be the full on Z51 was the hardest spring that you could tolerate....which I did install, regretably...
Mine is labeled Z52, but has the fast rack, big solid sway bars, 'steins and everything else. Now it has a 499 lb/in spring that easily qualifies it as Z51.....(buckboard)

I miss my old 230 lb spring.....:duh

I had never heard that the "Z" code also covered trim packages....I always assumed it was strictly suspension package code.

"Someone in Kentucky" had been drinkin' too much monshine. Z52 never replaced Z51. In the years Z52 was offered, Z51 was also available. Z52 was a the fat-bottomed geezer option for those who didn't want the stiff, harsh ride froim Z51 springs and shocks, but did want the wide wheels, the Z51 structural upgrades, the big stabilizer bars, Bilstein shocks (with less aggressive Z52 valving), HD cooling and the aux. fan, the oil cooler and the quick rack.

While Z51 was coupe only, Z52, by virtue of the base springs, was also available on convertibles.

Z52 came into being mainly because of dealer input on the Z51 as being too stiff but also having equipment the silver/gold chains set wanted.

 

[KLUTZ]

So, what can I expect the ride to be like with mine when I get it roadworthy? Soft, hard, bumpy, rearend sway?

 

[Hib Halverson]

So, what can I expect the ride to be like with mine when I get it roadworthy? Soft, hard, bumpy, rearend sway?

The ride will be comfortable.

If it's bumpy or the rear end sways, there might be some suspension components which are faulty or worn out.