Front spring questions

[highpockets]

I have read some of the posts here on this topic. I actually have a 58 Sedan Delivery..so the back half is 57, so I hope that qualifies me to be here..lol. I have read quite a bit about the Aerostar springs, but that 3" drop might be too much. I really don't want to lower it, just make it ride better. I am installing a 390 and C6, so that is heavy also. I don't quite understand the rates and loads of springs, but here is a little info. The CC850 is the Aerostar spring. .75 diameter, 605 rate and 1825 load. I found a CC640 that has .812 diameter, 622 rate and 2000 load. Am I correctly assuming this would be a little heavier spring? I understand the diameter, and kinda the load, but what is the rate? I don't want to start buying springs and testing,,I would like to only do it once, so any help would be greatly appreciated. Oh...it has 68 LTD disc spindles,,perfect fit and stock height, so that hasn't lowered it at all. Thanks.

[RICH MUISE]

I was going to welcome you to the forum, but I just realized you joined 2 years before I did!.
Welcome anyways.
I'm sure no expert on springs, but from what I understand the Aerostar springs don't ride quite as well, probably because of the smaller number of coils. There are enough guys on this forum with them though that will chime in on that, I'm sure.
How's the rest of your suspension...joints, bushings, shocks, etc.? They all effect ride quality.

[lalessi1]

A coil spring is actually a torsion bar. As the spring compresses the "wire" twists. The spring rate is the amount of force require to compress the spring 1 inch. The load is the total force required to fully compress the spring. The ratings are a function of the the length of the wire, the diameter of the wire and the physical shape of the spring. I doubt that changing springs will soften the ride, that was the intention in the design originally. To get the best ride, change to a "factory" spring that puts the car at the specified ride height. There are several springs available. BTW the FE engines are no heavier than the Y blocks, don't know how the transmissions compare. A spring manufacturer can wind a spring to match the original specifications and can help with the selection process.

[Ford Blue blood]

C-6 is lighter then the cast iron cased Ford-o-matic, the cast iron cased FMX and probably the Cruise-o-matic.......

[highpockets]

I never specified in the original post..I was looking to go with a variable rate spring. i have read quite a bit about how good they ride. My car was an original 6 cylinder/3 speed, so those are the current springs in it. I had a 302/5 speed in it last and it sat quite nice,,just a little low, but about right. I'm afraid with the FE, it will be lower yet. I have a set of original 58 wagon coils from a FE car that I was going to install, but they are rusty and pitted, so I was going to go with new ones. New originals are close to $200, I can buy the new Moog variables for under $70. I looked closer at the specs between the 2 options I listed above. I thought the 640 would be the better ones going by the rate and load, but checked the heights and they are 4" taller free height and 3 1/4" taller installed, so those probably won't work either. I could probably use the Aerostar 850s and put spacers above to reduce the amount of drop. I will do some more research and if someone here has experience in those Aerostar springs, I would appreciate some imput. Thanks again for the help. Oh...and the rest of my suspension is good.

[lalessi1]

Variable rate springs usually require more suspension travel. Obviously suspension travel is limited by design. My car had a 6/3spd in it originally, when I got it it had a 302/AOD. It now has a 390/4spd. When the previous owner put the 302 in it he heated the springs and collapsed 3 coils dropping the car at least 3", the car bottomed out constantly and drag over modest curbs. I put '59 Edsel springs in it and it sits a little high but I much prefer that. The springs were $50 bucks. There is a picture posted with Aerostar springs in "79 T-bird spindles with Aerostar springs",reply #12. The Aerostar springs look like variable rate, the coil spacing is different. The closer coils collapse first making the spring stiffer.