[Muttley]

Hey everyone,

I have a bit of a mutt of a car, 1969 el camino with a 1969 GTO front clip and interior. Powered by a 428 Pontiac with tri-power.

Seeing as some issues necessitated an engine rebuild (long story), I want to spruce up the suspension as the bushings are shot.

I was thinking of buying a set of geometry corrected tubular upper arms, new bushings and balljoints in the lowers, a new set of matched springs front/rear and anew set of bushings for the rear arms.

The El camino was originally a V8 car, but it must have been a small block as the 428 has the front LOW!

Can anyone recommend some springs that will take the weight of the big motor as well as drop the car nicely?

I plan on doing a full suspension upgrade in future, but I don't have the cash flow for the engine rebuild and the full kit at this time. I want to get the suspension fixed so I can drive this thing.

Oh yeah, it's going to be a cruiser mostly but I'd like to be able to drive it spiritedly if I feel the urge.

Thanks

[The Champ]

Worn out original Chevy small block springs would put you in the weeds with a Pontiac V8 under the hood....

A simple change to 1 or 2" drop '69 set of GTO springs should do the trick.

[chrisp]

Just use 69 chevelle SS big block springs .

[JLMounce]

What's your actual budget for the suspension upgrades? If your budget is limited, I would for the time being, avoid aftermarket control arms. You can generally make better handling gains elsewhere without incurring that cost. Especially if we're talking about a cruiser that maybe see's a back road every once in a while.

With an idea about how much you can spend, that would dictate my recommendations.

[Muttley]

Originally Posted by JLMounce

What's your actual budget for the suspension upgrades? If your budget is limited, I would for the time being, avoid aftermarket control arms. You can generally make better handling gains elsewhere without incurring that cost. Especially if we're talking about a cruiser that maybe see's a back road every once in a while.

With an idea about how much you can spend, that would dictate my recommendations.

Well, the budget is what it needs to get the suspension safe. I plan on doing a full suspension build at some point. But it’s not in the budget to do it right away. So, if there are affordable things I can do while I’m in there, I will do it.

I am debating on doing tubular uppers to correct the geometry. Or just rebuilding the arms I have and adding .5” longer upper ball joints and doing new rubber bushings. I’ve also been thinking about boxing the rear arms while I have them out to do the bushings as that’s pretty easy, just some sheet and a welder.

The only sure thing is a set of springs for the stance I’m after.

I know that’s not a direct answer, but I’d like to spend as little as I can, unless there is something that is worth spending the money on.

And yes, it’s mostly going to be a cruiser that sees the odd back road.

[JLMounce]

The first thing to realize about the GM SLA front suspension is that it's issues go beyond what control arms themselves can fix. They are part of the broader equation, but what they provide generally doesn't help in typical driving circumstances. Their benefits start to show when the car is pushed harder.

I don't typically recommend these, but considering you want to fully-reengineer this probably sooner rather than later I'd opt for a set of PST Polygraphite bushings in the factory arms. Do their full rebuild kit that includes the steering system rebuild. If your bushings are shot in the control arms, I guarantee the steering system is shot as well. Polygraphite isn't known for it's longevity because the graphite tends to eat away at the bushing material. But with this being a possibly temporary solution, it gets the benefit of a poly bushing with less deflection without the noise that comes with that bushing type. If you think that the bushings will be in there longer than 5-7 years, I'd opt just for rubber bushings, or go straight to delrin.

I'd then add Hotchkis 2" drop springs for big block A-bodies, front and rear.

As you state, add the .5" tall ball joint to the upper control arm. If budget allows, the car would also love a sway bar, front and rear (I like the Helwig bars).

Finally add new shocks. If the budget allows it, I'd go with a Koni Classic (red). If the shock budget isn't that high, I really like the Gabriel VST line of shocks. They'll work okay with the Hotchkis springs.

Last thing is a modernized alignment. You shoot for as much caster as you can get from the control arms (typically no more than about 3* positive). Shoot for -.5* camber and 1-1/6" total toe in.

That setup is going to ride and handle pretty well and it's not going to be overly expensive.

[389]

-SPC adjustable control arms Delrin for the top with a .9 tall ball joints and get the heavy duty couplings.
-SPC Lower control arms with a 1/2" tall ball joint.
-Lee 14.1 800 Series box with a 30 pound valve.. A 13" steering wheel works best with this box..
-Spohn Del Sphere rear control arms, use rubber bushings in the rear end upper locations.

Align it to these specs;
-Drivers side + 6.5 positive caster.
-Passenger side +7 positive caster..
-.25 negative camber both sides..
- Toe in 1/32 to center both sides..

-Brakes, keep the factory disc / drum set up but use Porterfield street performance pads and matching rear shoes.. I like the slotted rotors, I get them on e-Bay for around $125.00
- Put new races and bearings in the front..

[Muttley]

Originally Posted by JLMounce

The first thing to realize about the GM SLA front suspension is that it's issues go beyond what control arms themselves can fix. They are part of the broader equation, but what they provide generally doesn't help in typical driving circumstances. Their benefits start to show when the car is pushed harder.

I don't typically recommend these, but considering you want to fully-reengineer this probably sooner rather than later I'd opt for a set of PST Polygraphite bushings in the factory arms. Do their full rebuild kit that includes the steering system rebuild. If your bushings are shot in the control arms, I guarantee the steering system is shot as well. Polygraphite isn't known for it's longevity because the graphite tends to eat away at the bushing material. But with this being a possibly temporary solution, it gets the benefit of a poly bushing with less deflection without the noise that comes with that bushing type. If you think that the bushings will be in there longer than 5-7 years, I'd opt just for rubber bushings, or go straight to delrin.

I'd then add Hotchkis 2" drop springs for big block A-bodies, front and rear.

As you state, add the .5" tall ball joint to the upper control arm. If budget allows, the car would also love a sway bar, front and rear (I like the Helwig bars).

Finally add new shocks. If the budget allows it, I'd go with a Koni Classic (red). If the shock budget isn't that high, I really like the Gabriel VST line of shocks. They'll work okay with the Hotchkis springs.

Last thing is a modernized alignment. You shoot for as much caster as you can get from the control arms (typically no more than about 3* positive). Shoot for -.5* camber and 1-1/6" total toe in.

That setup is going to ride and handle pretty well and it's not going to be overly expensive.

I like this idea, I may look in to those bushings. What do you recommend for rubber bushings ? If I decide to go that way, I'd like to get something decent.
I can't seem to find any hotchkis springs anywhere, apparently they're plagued by supply issues. I notice BMR springs and UMI springs are in stock, but with BMR I worry about the weight of the 428 lowering the car too much. That would make it just like it is now LOL.

Any recommendations for other springs that aren't going to break the bank as they'll be somewhat temporary?

What do you think of the QA1 coilovers ? I could probably stretch the budget to fit them in and I'm thinking they'll probably work with the full suspension kit as long as I go QA1 in future.

Thanks for all the help, there's a ton of choices and it makes it hard to choose.

[JLMounce]

Originally Posted by Muttley

I like this idea, I may look in to those bushings. What do you recommend for rubber bushings ? If I decide to go that way, I'd like to get something decent.
I can't seem to find any hotchkis springs anywhere, apparently they're plagued by supply issues. I notice BMR springs and UMI springs are in stock, but with BMR I worry about the weight of the 428 lowering the car too much. That would make it just like it is now LOL.

Any recommendations for other springs that aren't going to break the bank as they'll be somewhat temporary?

What do you think of the QA1 coilovers ? I could probably stretch the budget to fit them in and I'm thinking they'll probably work with the full suspension kit as long as I go QA1 in future.

Thanks for all the help, there's a ton of choices and it makes it hard to choose.

Both BMR and UMI make quality components. If you're interested in their product due to availability, give them a call and talk about the concern with the weight. You can also talk with Afco racing and they may be able to custom spec a spring for you. What is most typical for a big block application is that the spring rates don't change, but they add a bit of free length.

I am not a fan of the coil-over conversions for several reasons.
1. It's not really a coil-over. It's a conical spring mounted on a threaded large body shock. Other than height adjustability, it doesn't really offer any benefit over a conventional coil spring paired with a quality shock.
2. Because the spring sits on a perch connected to the shock body, side loading from suspension deflection and normal bump/droop travel is excerpted on the shock itself, instead of in the lower control arm perch which is designed to keep things in place
3. The above also creates a poorer motion ratio than the conventional spring, meaning you end up needing more spring rate to achieve the same wheel control.
4. When utilizing the factory lower control arm, you're asking the shock mount to hold the entire weight of the car, as opposed to just shock loads that it's designed for. The control arm is thin in this section and designed to allow a shock to pass through, making it prone to bending, cracking etc.
5. Many of the lower end coil-over conversion pieces have a threaded sleeve that is either welded or interference fit to the shock body. That sleeve has a propensity to dislodge itself from the shock body and crash downward into the lower control arm.

If you decide you want to go in that direction, stay away from everyone's entry level offerings. You want to buy the nice stuff that typically has the threads extruded in the manufacturing process.

The only coil-over conversion that I myself would purchase as a bolt-in piece would be the Verishock coil-over conversion. It uses actual coil-over springs and a pivot ball mount that allow the spring and shock package to swivel up to 60 degrees, which eliminates the side loading issue and mitigates the motion ratio issue.

What I don't like about this package is the fact that once again you're still using both the lower control arm shock mount and now also the upper shock mount to hold the vehicle's weight. These are also pretty expensive.

https://www.cachassisworks.com/p-166...table-425.aspx

There are genuine reasons to employ a true coil-over system and if you're after that, I would focus on that when you start looking at the total package, including aftermarket control arms. When you do that, look at a proper coil-over system that works with those arms and includes an engineered upper mount system that replaces the upper spring perch in your frame.