Back in the 70's I used a pair of helper springs on my 69 Sattilite. I mostly
did it to cure a sagging rear end (on the car). It did the trick raising the rear just enough (1 to 1.5 inches) to give the car the original ride height.

I'm thinking of adding some helper springs to my 68 Dart. My question is
do helper springs increase the overall stiffness of the rear suspension?
Are there any bad side effects associated with helper springs?

Just to be clear I'm talking about a kind of bolt on half leaf. They sell them
at Advance for 25 bucks.

your just adding more metal to flex so yes it would be more stiff. this is a good option for towing too. i got some new leif springs to cure this and it barley raised them, if any at all. you could always crank down your torsion bar screws, get an alignment, and go for the low look, then add sway bars to handle the corners...

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'72 Valiant DD for over a decade-225-Disc brakes, big T-bars, big Sway bars f/r, carter bbd/super six, GM HEI, 2- 12" subs in trunk, 1000w amp...
'77 cherokee cheif widetrack-360-33x12.5 tires-no lift. keeps driveway dry-project/backup DD/mudder

Thanks dank, but Im running 13" rims with 185/70s so the car is plenty
low enough

I tried that.... but there was not a speed bump within 100 miles that did not fear me when I did so....

Not to mention, the moment you put weight in the car... are are on the ground.

Helper half-leafs are good if you are simply trying to retain stock height, but not much good after that. You may run into an issue later on where you need to keep adjusting them up, as they wear, or if you suddenly throw 600 lbs. of people (or other stuff) in the car.

I would go with Air Shocks.... adjustable to almost any height, and they are easy to install. Adjustment is simply adding or subtracting air pressure from the shocks. The only downside to them.... is that they cost a bit more than $25.

~THOR~

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1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

The other downside is that air shocks will break the upper shock mount over time.

Bring in the reinforcements!!

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing