[JKGTO]

Looking to upgrade the front suspension on my '68 GTO convert. Its a stock 400 auto car with A/C, PS, PDB, and Hideaways. Just want a better ride and maybe lower it a bit. Don't need anything fancy. Can get the QA1 GE401-10550B for like $360. That's their economy setup with adjustable ride height. Who has put these on a 68 or 69 convert and what do you think about them? Go with 550 springs or maybe 600? Or a better alternative for the $$. Want to get it right the first time . Thanks, Jim

[JLMounce]

The better question to ask is what your intended purpose with the car is? Are you just wanting the car to sit a little lower? What's your ride comfort requirement? How is the car going to be driven?

Other's disagree, but coil-overs for these cars are a compromised design and if you're not looking for every 10th at a competitive auto-x event, are probably not only not necessary, but may be a waste of money. The big issue with retrofit coil-overs is that they aren't a true coil-over at all. They are a standard large body shock with a threaded perch. The shock mount is virtually identical to that of a normal shock, but you're now asking that portion of the shock to take the entire load of the car, rather than just damping loads which are significantly less. This doubles for the factory lower control arm which is not designed to have the shock mount carrying the car's load. So while you can get the coil-overs for around $360.00, you also really need to be thinking about lower control arms that are designed for a coil-over as well. It snowballs from there depending on which lower control arm you purchase. If it has built in positive caster (some do, some don't) you may also need a geometry corrected upper control arm to keep the wheel centered in the wheel well.

Now, instead of spending $360.00, you're over a grand deep in many cases and that's just the front.

If you don't need to continuously change the ride height of the car, or make corner weight adjustments, there's not a lot of value in the adjustable feature, when you can achieve a lowered stance through use of springs or drop spindles.

If your goal is just a lowered stance, but you want to retain a ride similar to what your car currently provides, while improving handling a bit, I would spend that money on addressing the car's geometry issues.

Choose a spring with just a small amount of drop and just a slightly firmer rate than your factory springs. Then add tall upper and lower ball joints to the control arms. If you go with a 1" lowering spring in the front, with the addition of the tall lower ball joint, you'll lower the car about an inch and a half. Then do a spring in the rear to get it to sit how you want. A 2" lowering spring in the rear will get the car sitting fairly level, while that same 1" lowering spring will give it a bit of a rake.

Add a quality shock of your choice and give the car a modern alignment. If you need more wheel rate in the corners, add a larger front sway bar and a rear sway bar.

This setup is cost effective, doesn't re-engineer the wheel and will provide you with a noticeable increase in handling potential, while being as reliable as your factory suspension setup and not destroying your ride quality.

[JKGTO]

This is just a driver/cruiser. Won't be driven hard. Just want it to ride better and take the bumps in the road better and be more stable. Don't know if I would like it lowered or not. A lot of threads about people not liking the springs they bought and the ride height. Also just bought some Firestone GR70/14 radials to put on it.

[67GTONUT]

Originally Posted by JKGTO

This is just a driver/cruiser. Won't be driven hard. Just want it to ride better and take the bumps in the road better and be more stable. Don't know if I would like it lowered or not. A lot of threads about people not liking the springs they bought and the ride height. Also just bought some Firestone GR70/14 radials to put on it.

If you are staying with 14" tires..... Coil Over's are total overkill for how you are going to drive this car....

Just make sure all your front end components are good..... a quality shock and drive her....

[JLMounce]

Yup those 550/600 lb springs you’re looking at are going to be stiff. Add a shock body with a lot of compression damping and “ride quality” isn’t what you’re going to receiving.

Definitely agree with 67GTONUT, no need to reinvent the wheel here. Make sure your bushing are I. Good condition and put a quality shock in the car.

[JKGTO]

So the stock spring is what lbs rate? If I did a 1" drop then how much more spring would I need? Need modern alignment specs for lowering or radial tires or both? What would those specs be for this car? I want to get all the parts together before I tear apart the front and then see how it sits to decide if rear is ok or needs changed. At least I know now the coil overs aren't what I should get

[JLMounce]

I believe there were some variances there depending on the car and it's equipment, but they are likely around 300 lb springs. There isn't a completely direct correlation there however because the motion ratios between the factory setup and a coil-over conversion don't match.

For you, I'm liking the Global West front and rear springs.

http://www.globalwest.net/gto-grand-...il-spring.html

These are going to be modestly stiffer than stock and lower your car around 3/4" to a full inch. I would pair these with a set of Bilstien HD shocks. You should also inspect your rubber pushings in all of your control arms and replace as necessary.

This type of setup is going to get rid of any floatiness you may be feeling and offer just a tad bit firmer ride without being harsh. The lowered stance should look good without giving away the somewhat classic stance of the factory height springs. You're also not removing so much travel that you run into issues on bad pavement.

Alignment specs below.

Camber: -.5* to -1* depending on how you drive. Less for a cruiser, more if you like spirited driving on twisty roads
Caster: +2*
Toe: 0 or 1/16" in

A note on caster. Realistically, you want to get as much positive caster into the system as you can, evenly across the corners, or whatever they need for a road crown adjustment. If the tech can get more than 2* in there without a mile long stack of shims, do it. Most factory arms will be hard pressed to get much more than that however.

Upgrades from there that don't meaningfully impact ride quality are going to be the addition of larger sway bars and tall ball joints to start correcting camber curves. Based on how you're using your vehicle, I see those as probably a waste of money however.