I've posted this info several times over the years and thought it would be helpful to post it separately and link to it from our Help Page.

NOTE: The 235-75R15 is often used when running radials on 1963 and 1964 Cadillacs.  It will be about 1" shorter than the factory 8.2 x 15 tires and will effectively drop the ride height about 1/2".

If your car does not seem to be sitting at the right height due to tired coil springs, etc.,  you can check the suspension standing height per shop manual in the Chassis Suspension Chapter 4.

For the front (1963 &1964 Shop Manual page 4-15, Fig 4-21), measure from front rear lower control arm flange up to the center of the hole in the frame as seen in the shop manual illustration. Correct Standing Height Ranges are listed by body style on page 4-32 in ship manual and seen at top.

For the rear (1963 & 1964 Shop Manual page 4-15 Fig 4-22), measure distance from top of rear axle housing straight up to lower underside surface of the frame. . Correct Standing Height Ranges are listed by body style on page 4-32 in ship manual and seen at top.

A coil spring with over a thousand pounds on it for 50 year is going to compress. Metal becomes fatigued and even thought these are stout coil springs they will compress.

Also, keep in mind that there were many variations on the springs depending on whether or body style and if you had regular or HD springs.  For 1964 you had 7 different springs (4 regular and 3 HD, and 5 on the rear (3 regular and 2 HD) and 2 variations of leaf springs on the commercial chassis leaf springs. 

NOTE: Comparing the height of uninstalled springs, especially New HD springs and old regular springs is basically Meaningless!  You can take a new HD spring and sit next to a comparable regular spring, both on level ground and uncompressed, and the HD spring  will sit or so lower than the tired old regular spring but when you go to install in the car will force the car up to the proper height. When I first ordered my CDV HD springs from Kanter I thought I had royally messed up when I compared the two, but once I installed the spring I was greatly relieved.

For reference the springs are listed on page 4-32 and 4-33 in the 1964 Cadillac Shop manual.

Here are scans from those pages:


Here is a picture showing the Front Standing Height on my 1964 Coupe DeVille at almost Exactly 8", just under the 8 1/4" upper limit: 

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Now included on our help page - www.help.6364cadillac.com

Bumping this up since there is a lot of coil spring discussion on the forum. There were 7 front and 7 rear coil springs used originally depending on body style and regular or HD spring used. This is on the Help Page under:

- Suspension Standing Height and Coil Spring Specs

Kanter now claims they exclusively sell 1964 Cadillac coil springs in "heavy duty" format.  Effectively eliminating any other option for ride. 

Are you saying they claim to be the only seller of HD Springs, or that they only sell HD springs? I installed the Kanter HD springs way back and was very pleased.  I believe all the online sellers actual get their springs from the same supplier. 

Jason, i knew you would call me out for clarification!  To be clear, Kanter claims that they "Only Sell HD Springs"  The person I spoke with said there were no longer options for lighter duty springs, therefor "they" stopped making them.  I am not sure who "they" are. 

This leaves me with the following question.  If there is no longer an option for the lighter duty springs.  How do I KNOW that I am receiving an HD spring.  Is there some indicator besides the original color coding that Cadillac would have used.  such as an MFG number or something?

I put in new springs years ago, and the ride height was good, but the loading capacity was just not there. If I had back seat passengers, the car would squat and handle poorly over bumps. Maybe the HD version will be better.

Nice, thank you, Jason this is useful.

i have a question , that sorta has me worried about my cadillac. heres the link;

https://6364cadillac.ning.com/forum/topics/what-could-be-causing-th...

thank you

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