Variable Rate Cargo Coils
 

These are Moog CC501 rear springs. They will fit in the back of 68-72 A Body cars as is. The top of the spring has the coils wound tighter than the bottom. These springs can also be made to fit the rear of a 64-66 A body by using a cutoff wheel and cutting the pig tail off the top. If you cut the end of the spring even with the spring that came off the car, the spring will be the same height as the stock 64-66 rear spring. This should raise the rear of the car a little bit as the spring won't compress as easy as the stock springs.

Good tip Ken.

I have used variable rate springs extensively on motorcycles thru the years, with great success.

Les

bottom of spring is tight coil.

It's the top that has the tight coils. I will pull out the directions to be sure. I have another set in a car. Either way, they will work by cutting a pig tail off. The plate they use on the bottom of 64-66 cars fits the pig tail.

The directions say, close coils install the tight end upwards.

I have not tried it but you might be able to lower the back of the car down by cutting coils out of the close coil end on 64-66 cars.

tried it your way and won't clear tailpipes, and shocks

Are you sure you have the spring in the correct position? The springs is indexed on the top. Both the stock spring and the CC501 are 6.75 inched in diameter.

This is a 65 rear end with a stock spring that has never been removed.

See where I have the tape, that is where the spring needs to be cut on the top to be used in on 65 rear end I have posted in the above picture.

Don't have any '64-'66 springs to look at, but in Engineer's pic it looks like, and I had the impression of, that the springs are taper-wound, and I know the later ones are straight. Could this be the issue with the clearance?

Engineer does not have any pictures posted, those are my pictures. In order for him to get the springs to fit, he must have cut the pig tail off the bottom. How would he be able to correct the mistake once the pig tail was cut?

It's a common mistake to install variable rate springs upside down.

Quite right about the pictures, I just didn't look carefully. Sorry.

This is the top of the rear spring pocket on a 65 frame. You can see where the spring should be indexed.

Bump

Thanks Ken K this is great help and savings of bucks as Coil Spring Specialties have good stuff but are more expensive...
Ordered from Summit today $60 good deal !!!
Thanks
Eric

Northern Auto Parts sells them for $44.00, that's where those came from.

ken k do you have recomendations on 68 lemans convt. rear springs? was going to order a set from espo springs and things. i like a factory height or slightly higher stance

The listing for the CC501 springs is a 67-70 4 door. They won't compress as easy with the weight on them so the back end will sit a little bit higher. I don't remember the next step up but I think the number is CC625, they are 2 inches taller with a higher rate.

I think Maurader had a set of CC501 springs in the back of a convertable.He could probably tell you the difference.

thanks ken, got your pm. who makes and who's the dealer for the cc501
chris

cc501
 

If you go to summitracing.com and type cc501 in the search box, the springs pop up.. they appear to be moog from the part #.

They are Moog, I have that in my first post. www.northernautoparts.com has them for $43.99. You can put in the part number there also.

I put a set of those on my 67 Tempest Sprint coupe about 20 yrs ago.
It still sits like a low rider and Ive taxed the load bearing of these springs
to the max.(it would surprise you how many motors and heads you can get in this trunk).
I havent changed the front stock springs and it sits low and level.BTW my car is an A/C car.

So, what would the front and rear stance of these progressive springs look like on a 70 GTO coupe with a 400? I am wanting more of a G Machine ride and stance and handling, so would these fit the bill? I was thinking about installing Eibach Progressive springs but these would cost me half the price.

I don't know what the stance on a 70 GTO would be, it must be at least equal or better than stock. There are spring rates, does Eibach supply them?

This is what I found regarding the Eibach GTO Progressive Springs:
GTO, V8, Small Block A-Body 68 - 72; Lowering Kit drops vehicle 1.3" in the Front and 1.3" in the Rear. I could not find spring rate?

A GTO and a small block can't be lowered the same amount in the front with the same springs. A Pontiac engine weighs more than a small block engine.

I agree. I believe that they are generalizing classification of the Pontiac engine of all cid's as a small block compared to a Chevy Big Block.

That's the problem with a lot of the aftermarket springs, they are geared for either big block or small block. Also one stance fits all instead of custom fitting the springs.

My car definitely sits higher in the back with these springs and I liked the look much better than the stock squatty stance. I lowered the front about 3/4" - 1" with the Hotchkiss "big block" springs which may have made the rear look a little higher yet. I am running 295/50x15s in the rear which are about 26.7" tall. I'm glad I didn't lower the front any more since I have already bottomed out on the new Hotchkiss front sway bar twice.

I should have the motor back in next week and may make some additional changes in the stance at that time since I lightened the front just a little with an aluminum intake manifold and a high torque mini starter. That may not make much of a a difference however the new rear tires are 285/40x17s and are 26" tall and with the Judge spoiler I added I think the rear might look better just a little lower...... I'll let you know how it turns out and post some pics when I can.

Here's cc501's in action
 

Based on this thread, I purchased some moog cc501's from summit for my 1970 GTO convertible. The front springs are original and a little tired.

Personally, I'm not thrilled with the stance.. I'd prefer something slightly higher. (This is with a pretty full tank of gas). Especially since I plan to replace the front springs with stock.. which will raise the front significantly (I have another 1970 GTO with new springs front and back, and the front sits maybe 1.5 inches higher than this car).

Note that this picture was taken 10 minutes after the springs were installed, so the rear is likely to go lower over the next month.

What the next step up beyond cc501?

Your car has a little bit of rake to it. That would not happen with stock rear springs.

Unless the ride is real bad, I would not mess with the front springs. Most people try and get a stance like that if they want to change it. Bigger rear tires will help fill up the wheel wells.

I'm going from memory since the big spring chart disapeared from the net. I think the next step up is CC625 for the rear.

Those rear springs are shifting some of the weight toward the front. Maybe that's why the other GTO sits 1.5 inches higher in the front.

If you have 2 1970 GTOs and the rear springs only take 10 minutes to change, try using the CC501 in the rear of the GTO with the new springs and see what happens.

"Getmygoat" - I think your stance looks pretty good now. Do you really want to raise the front an inch and a half???

When I had the variable rates on the rear only the car didn't corner nearly as well as it does now after I installed the stiffer fronts. The front felt mushy and not as responsive in the turns before, while the rear of mine was stiffened up from the variable rates and the sway bar....

I think the stance looks good too. If the front springs are not up to the task, I would try and figure out how to get the same stance with new front springs.

My other '70
 

Here's a pic of my other 70. It has brand new stock replacement springs from AMES in the front.... It also has rear springs purchased at ESPO.com as 2" over stock.

Most people would agree this has too much rake... back is too high, and I agree.

Getting the right stance with springs is difficult, I can see why people take the easy way out and use air shocks.

Do you know the rear spring numbers that you bought from ESPO? They look more than 2 inches over stock. You can get the springs from bigger cars to work on 67 and later cars. I think if you put the CC501 springs in the back of the blue car, it will lower the back of the car.

I removed a set of rear springs from a 69 GTO that had 10 inch wide wheels and big tires that stuck out past the wheel wells. I had to use a pry bar to remove the springs because the suspension was maxed out. I still have the springs, I used them in back of a 67 El Camino to see what it would do. I had to use a spring compressor to get them in. It maxed out the rear suspension on that also. I have no idea of the origin of the springs.

blue GTO rear springs
 

I dug through my pile of receipts for the blue car and found the ESPO invoice. Those 2" over stock springs... are cc507.

cc507 seems more like 6 inches over stock to me

i don't know why this has to be so difficult. i was going to buy the stock springs from espo for my 68 gto conv. ($60.00), but now i'm not sure. i like a little stance but not too much. maybe i'll try the stock plus 1" over if they make it. any more info would be helpful. i'm not sure what stock height was like in '68

That has to be a good 4-6" over stock height, not just a couple.

The picture in my Moog catalog shows the cargo coils have the tighter windings at the top.

I grabbed this catalog (1986 copyright) about 8 years ago so I could do some 'homework'.

Ken, do you know the wire diameter of the CC501...the catalog doesn't list it.

The reason I ask is that I put in some .565" wire coils and it's just too stiff to go to the track and have any traction with my current tires.

Thanks.

The instructions that came with my 501's also said the tigher windings go at the top

Getmy goat,

What are your tire sizes all around? I have a '72 vert that has 235/60/15 on the front and 275/60/15 on the back and will be replacing the rear coils on. I like the stance on your vert, I think my 275s on the rear will raise it just enough to get the rake I want.