Ride quality

[Yadkin]

The springs will definitely create a harsher ride. I'm not sure of the amount of coils in a stock spring but you might want to count yours. In an effort to stop the wallowing in corners when driving a classic car people put too stiff a spring rate into the car. Creates an effect like driving with no springs, doesn't matter what shock you have at that point since there is no dampening to be had with too stiff a spring. The fact yours might be sitting taller makes me believe someone put in a bigger / stiffer spring and you'll never get a cushy ride. But it'll corner better or should as there won't be as much side to side wallowing.

+1

I had a pair in the front of mine, advertised as "heavy duty", that were so stiff they were topped out when installed. First I cut off one coil then reinstalled. Then a second. I finally got a new set from a different vendor and had the option of AC car vs non-AC car, and chose the latter. Although I have AC now, the tiny Sanden style compressor mounted low on the passenger side weighs nothing compared to the OE breadbox compressor mounted high on the driver's side.

Side-to-side wallowing can be taken care of with a larger front anti-sway bar along with a rear anti-sway bar. That's what I ended up with. OEM type shocks and it rides nice and handles the curves very nicely.

[Frango100]

Just checked the rear springs. They have both 10 windings and the steel is 11/16" thick (measured on the paint, so will be a little less).
The spring seems to be quite thick, when i compare it to the springs on my jeep. The jeep only has 9/16" thick springs (2004 Jeep Grand Cherokee), and the weight should not differ that much.

[sidewalkman]

Just checked the rear springs. They have both 10 windings and the steel is 11/16" thick (measured on the paint, so will be a little less).
The spring seems to be quite thick, when i compare it to the springs on my jeep. The jeep only has 9/16" thick springs (2004 Jeep Grand Cherokee), and the weight should not differ that much.

Next time I'm near my car I'll have a look Franco, But remember our cars are 2 tons of fun!! So they're heavier than a jeep and would require heavier springs, but yours seem really large to me.

[Frango100]

Thanks Scott. When I have some time, I will remove the rear shocks and springs and feel if the suspension arms will move freely. I was just reading yesterday about the problems an other member had with binding in the rear suspension. Then I can also measure the exact sizes of the springs, in case I will need to buy new ones.
In the original 58 manual, the roof height was given as 54" and a bit, so my bird is quite close to that at least.

[bird 60]

I was curios about the weight difference, & it turned out that the Jeep is 200 to 500 lbs heavier than the T. Bird.

Chris......From OZ.

[Frango100]

Just checked it now myself as well. The T-bird weighs 1682 Kg (3708 lbs) and the Jeep 1806 Kg (3981 lbs). So that makes the spring dimension even further out of proportion for the T-bird.

[pbf777]

Trying to determine load carrying capacity via a measurement of spring coil winding diameter, length, winding count or wire diameter and not knowing the metallurgy or tensile strength (and other considerations) makes for a difficult to impossible comparison process of the spring's load carrying capacities or expected ride quality.

Assuming we have a constant rate spring, good test would be to load the individual spring unit with a known weight value and record the difference between the unloaded spring height vs. loaded height (preferably several inches, as the accuracy improves with distance). This dimensional distortion can be conveyed as the "spring rate", the spring's unique load carrying value, for comparison.

With a progressive rate spring it will be necessary to load the spring, establishing specific reference points throughout it's as installed and applicable travel distances in order to realize the experienced varying "spring rate". Scott.