I am looking to raise the rear of the car maybe an inch or so. It sounds really easy to change them, just pay attention to how they are clocked is the info I found. I will change the rear shocks are well, thinking maybe Monroe Sensatrac for them. How much do the Cargo coils raise the rear? Anyone have a part number? Thanks.

 

Those type of springs raise the car 1.5-2.5 inches. I think the CC501 is the part number. For shocks, look at KYB GasAdjust shocks.

 

Amazon shows the Moog 5385 as the heavy duty option. Here are the specs, of course no specs for the regular duty 6321. The 5504 KYB looks to be the rear shocks are are only slightly more money, so I can go that route.The CC 501 is stiffer and says it doesn't fit my car. One of the reviewers used them on a 68 GTO and wished they were an inch higher. It's spec are the bottom one.

• Spring size: Inside Diameter 5.570", Bar Diameter 0.593", Installed Height 9.0"
• Load rating: 602 lbs

The CC 501

• Fits 1967 - 1972 GM vehicles
• Spring size: Inside Diameter 5.53", Bar Diameter .61" Installed Height 8"
• Load rating: 810 lbs.
• Pigtail ends

 

This is a good cross reference of moog springs.
Moog Coil Springs | Moog Suspension Parts (moog-suspension-parts.com)

 

If you like the current springs they selldifferent size spacers to go under the spring.

with your engine iwould invest in better shocks, like koni or bilstein. I consider monroe to be more every day driver than performance.

 

Thanks, very helpful. The CC501 come in at 8" installed height. The othe Amazon suggestion, the 6321 is 8.5" installed height with a 689 pound load rating. I would like it higher on the back and I do carry two spares and extra parts in the trunk. Not sure how well the spring spacers work, never seen one. Even an extra 2" over what is in there would be no issue for height, what is the stock height supposed to be? This will be the lone suspension tweak for this year, too much money going into the drive train and body. It handles quite well for a 50 year old car and stops OK for 4 wheel drums. Thanks.

 

I only found one Koni rear shock, only one, not two in stock and the Bilstein only fronts on Amazon. Both are 3 times the price of the KYB, Monroe and Gabriel are slightly less than the KYB. I will have to decide on shocks and do some reading on spring rates and height on handling including ride quality.

 

I'm running the CC507 springs on mine.

Before


After

 

Thanks those look like a 10" height spring and the highest rate so far at 895 pounds. I don't mind it higher like your car. How is the handling vs stock?

 

I have since raised the front also. It drives fine with no wheel hop. I also redid the rear with UMI tubular control arms, sway bar, and poly bushings. Shocks are KYB's and I added a lunchbox locker to the 3:08 open type O rear. I did not like the Monroe shocks I installed 10 years ago. The advantage of the KYB shocks is they are longer for the additional ride height.

 

Those look good too. Here is my current stance. I will go with the KYB shocks since they are actually available.

 

I think you'll like the KYB shocks. If you change the springs, you'll need taller tires to fill up those wheel wells in the back.

 

I have 275/60R15 Cooper Cobra's on widened Pontiac Ralleye 10" rims for the back. The front are 14x7 and would get new 225/70R14 Cooper Cobra's to match the back.

 

This picture hsows how my car sits.
245-60-15s all around
Moog 5536 front springs
PST "442" rear springs, I don't have specs but think they are similar to Moog 5409

 

The 5409 is the shortest of all these at 7.5". The whole constant vs variable rate is clear as mud. Some say it is superior in every way.. Other say it will provide a better ride but at the cost of handling. They argue the shock absorbers can't react to the uneven spring unloading properly. I am between the two tallest springs, one is constant, one is variable. I will decide and buy on Friday.

 

I have often contemplated swapping the PST springs for Moog 5409s to see if that would drop the rear a bit. I think an inch lower would look much better.

 

Ride height is personal taste. I agree, that convertible looks better even, than significantly higher in the back. Your car looks good. I want the back higher than the front but not a ridiculous amount. I may have to measure the installed height of the current springs. The back needs to go up 2" inches for sure. The front is at least an inch higher. There is 2 sizes smaller tires on the front, so about an inch shorter in the pic.

 

Moog 5415 springs are what I have under my '72 ragtop - they're variable rate springs, v. cargo coils which may tend to be bouncy if you're not weighed down in the rear - a VR set may be better choice for your purposes.

I also run the Koni street shocks (orange set) all around - not harsh, great handling characteristics and I like them the best out of KYB or Bilstein.

My wheel/tire combo is 17x8 with 4.5" backspace and 245-50-R17 tires all around. I run 1" spacers on the rear for a slight stagger look and there's plenty of rear wheel well clearance .

 

I will see if I crawl under enough tonight to try and get the current spring height. That Moog site says the 5415 are Constant rate and not available on Amazon. I like the sounds of the variable rate springs overall. The Koni and Bilstein shocks really nice but are 3 times the cost and not even currently available on Amazon, at least the rear ones.

 

I looked through the Moog spring data that I have archived and the 5385 showed up as an alternate entry for the rear on nearly all 1970-1972 models.

Spring # 5385
Installed height (inches): 9
Load Rate (lbs): 602.3
Spring Rate (lbs/in): 167.5

Ya know, after looking at the data and seeing the above, those PST springs that I bought way back when that had an application saying "all 442" may be similar to the 5385 and not the 5409 as I previously thought (and now I don't even know why I thought they were similar to 5409s). Hmmm.

 

From my measurements, my current springs have around a 8.5" installed height. I measured through the center hole at the top of the mount to the bottom of the spring. Pretty sure the 10" springs are what I need to lift the back end where I want it.

 

My Moog database shows the only springs with 10” installed height are Cargo Coils.

 

Yes, the CC507 look like the ticket for me. They are a variable rate spring so they should ride decently. I just don't see the same height or 1/2" making much difference over the current stance.

 

If you're going to buy springs, buy them local so you can exchange them if they are not what you want.

 

Not bad idea, in theory. Napa has them on their site, shows them as unavailable for twice the cost as Amazon. Nearest Napa and a couple of others part places are a half hour away, in a city of maybe 20,000. We have one in town, the Pandemic killed the other one. Our population is pretty low up here, our Province, which is huge, biggest city is only 250,000. I see the lift difference of the CC507, even if it is a different body style, his car had about the same rear squat. Only $100ish for the pair, a drop in a bucket compared to what I have already spent on this car. I can either hang them on the wall or give a member here a deal, if I don't like them. I will order them and KYB shocks this week.

 

I am sure glad I went with these springs. The driver's side was more collapsed than the passenger side. I went to 225/70R14 from 205/70R14 front and 225/70R14 to 275/60R15 rear.

 

That looks like a perfect match to the front height. Good job.

 

I agree. Anything less would have still left the back end low.