has anyone ever used the AcDelco replacement springs on their Iroc z's, i know most people use moog 5662/5665 springs but was just wondering about these as summit racing and rock auto both carry them
rear - https://www.rockauto.com/en/moreinfo...035548&jsn=265
front - https://www.rockauto.com/en/moreinfo...35548&jsn=1379

 

AC Delco OE replacement parts are always good. Should restore factory performance. New bushings in the a-arms, strut mounts, ball joints, and sway bar end links too while you have it apart as the originals are now 30+ years old, rubber doesn't live that long. This is great for helping restore factory ride and performance. Also a great time to replace struts if they're old, worn, or just not the performance level you're looking for. Struts/shocks are one thing you can't spend too much on.

The specs of the front springs look good, the front rates are good and a constant rate. I don't really understand the rears rates they listed as 518 lbs is higher than about any race spring I've ever seen. 100-150 pounds is around stock range and works great for street cars. My rear weight jacks have 250# springs for reference. Rears you've shown are also variable rates which works fine in a street car but I'd get a constant/linear rate if performance is your goal.

There's not one clear answer to your question really. The "best" springs for you and your car really depends on your goals for the car and what your expectations are from them.

 

AC Delco can span everything from an original equipment part, as in the real deal parts the car left the factory with, to whatever you'd find at your local Auto Zone under a no name label, except stuffed into an "AC Delco" branded box. It's always best to assume you're buying a rebranded part to avoid disappointment.

I wouldn't be the least bit surprised if the "AC Delco" springs are "Moog" springs in an AC Delco box.

 

it does say in the description that the rears are 500 lbs. (per pair). was afraid of using the moogs everyone uses because of sitting higher than normal, i just want it to sit and ride like factory, maybe just a little stiffer.

 

Which did you end up getting?

If you got the ACDelcos does it sit the way you want it too? Looking to do my own.

 

not yet been too cold here in Illinois but here really soon tho, still haven't decided yet but still leaning towards the Ac Delco's, their cheap enough and easy enough to change in the rear, that's where i'm starting 1st.

 

I used AC Delcos this last time. Sit a lil high so I cut em down bout a round. I like em

 

dmccain did you use the ones i have listed at top of thread and how much higher over stock height.

 

Just about positive i did. Seem like 3/4 - 1 inch was a happy medium.. My stock ones were a full 2in shorter but I'm sure some wear + settling them being 89k stock springs.

 

I ended up buying the ones you listed with some Koni Yellow shocks.

We shall see how it sits when I get my rear back on in 2 weeks or so.

 

Keep us posted, I too am shopping for shocks and springs for my 85 IROC...I've also been told that the Koni Twintube (8241 1140 Sport 93-02 Camaro) will fit into my 1985 IROC, anyone want to confirm or let me know if they have used them?

 

just ordered the rear ac delco springs #88913786 and the kyb gas adjust shocks, suppose to be here tomorrow so hopefully get them in this weekend and i'll let ya know what i think of them.

 

Hmm, I'm kind of worried about the springs, it seems they may not be a good match for the IROC:

This is what they replace according to wholesalegm




Please provide pictures of ride height and what you think the general feel is like when you get them in!

Hopefully you can save me from a return!

 

summit racing shows it's for them and others, i think these days manufactures make them to work in most vehicles nowdays, 500 lbs. per pair is higher than stock for an iroc, we'll see, fed ex be here today with them

 

I'm over thinking the springs as well, and here is my research...

 

The problem you run into with any aftermarket spring is that they're not application specific. You're talking about if they're correct for an Iroc, when GM used 3 or more different spring combos on virtually identical Irocs in the same year. Most aftermarket springs are intended to fit multiple applications. They're a "one size fits most" solution. They sort of fit a wide variety of applications, but on the flip side they don't fit any of them perfectly.

You can do a reverse search to see what cars a part fits on Rock Auto by clicking the part number in the catalog. The front springs say they fit thirdgens and S-series trucks, the rears supposedly fit 82-02 F-bodies. Given that info, I wouldn't expect them to be a great match to a performance oriented thirdgen.

This doesn't just apply to AC Delco, it's the problem with Moog and other springs as well. They're a generic spring that will work in a pinch, but a far cry from a new original equipment spring.

 

How do we know if we actually need to replace the springs any how? Is everyone just replacing because of age?

 

Im replacing because of age+ im taking the rear end off so ill be taking them out anyways.

What is the ideal replacement spring then? Does it involve lowering? Or are they all imperfect in different ways?

 

I have both the front and rear. I installed the rears in my 1987 Z28 iroc in the fall to replace whatever spring was in there. I think they may have been lowering springs as the car sat low and rode rough. They brought the rear ride height back to stock and rides better. Whatever spring is in the front still rides rough and pounds over bumps. I never got around to installing the fronts as the car sits level. I may do them this spring.

 

Well that's a bit reassuring, have you noticed a difference in oversteer?

 

just got mine on the rear and gotta say i'm very happy with them, compared to the old original ones it sits actually the same height. so over time it'll prob drop a 1/2" or so. handles great, we have a curve outside of town thats sharp and is 45mph, i went in at 65mph and came out at 78mph, curve total length prob bout 300ft total. made me Happy here bout a month gonna change out front also

 

This is good news! Looks like I get to keep my springs!

Thanks for the thread!

 

Hahaha, drive fast and speed into the turns! Appreciate the feed back, helps to know that the ACDelco springs are acceptable. I’m using the bump stops when the kids are in the back seats. Hey, did you replace the spring insulator, or not necessary? Just curious before I start ordering parts...

 

I was considering doing the heater hose trick for that if mine were shot. Wont know until tomorrow.

 

Good deal, I am jerking around with the interior. Just got the headliner, sails, and sun visors done. Still putting them back in. Kinda weird to see the contours again, with the old fabric hanging, very happy with this repair.

 

Yeah, while I have my rear end out, I think I am going to dynamat the rear end a bit since the carpet is up already, might do some rust proofing while im at it. Project never ends! That red looks pretty nice...

 

nope mine were still in really good shape

 

Pic of original and new Ac Delco's, exactly same height.