Quote:
Originally Posted by Shiny
Beautiful cars, thanks for the pics and info! This helps a lot.
What should I assume for "original spring"? Would it have been closer to the 5401 or 5413?
That looks great to me. To replicate this, a Moog 5401 and a 1" spacer might do it but depends somewhat on tire diameter.
What is the tire diameter? Any idea what you have in the front?
The Moog specs suggest the "heavy duty" 5413 would also raise the car about an inch over stock. I'm squirrelly about this, though, because there's a chance what I have now is a 5413. I will measure the wire diameter today and check to see if it's fixed or variable rate, like a CC507 or something...
That looks great too! What diameter are your tires?
I found a receipt that says I installed 5440 in the front. I will look up the differences and see if my front is also jacked up some. I really don't want to swap front again... was not a fun project.
The stiffness goal is difficult for me to guess what I want.
5401 - 128 lb/in.
5413 - 166
As you note, the 6319 is even softer than the 5401, reportedly 119 lb/in.
UMI makes a case for their 130 lb/in in this blurb:
Link to UMI Tech Article - "GM A-Body Spring Height Guide"
For your variable rate CC501, it's probably hard to know the "effective" or "instantaneous" spring rate at installed height but the intent was probably to have it be somewhere in the same range of 128 to 166 but it may also have been "stock" on a wagon that had more weight over the rear. This might actually put it at the low end of that range with your lighter car.
As to the effect of stiffness, I can guess at the "feel" but hard to know without riding in both. I don't want it to feel like a truck but I assume the 166 lb/in was standard in a GTO or with a "Ride & Handling" suspension option like the Y96 OPH mentions. Is this a safe guess?
I like the idea of starting low and using a spacer to increase the height if I don't like it. Thanks for that!
Mike |
As far as I can tell my springs are the originals or they were changed out a long time ago. I’m running 255/60R15 in the rear with 27” diameter and 235/60R15 with 26” diameter. The center of my front wheel well measures 26.5” and the rear is 27.5”
I bought the 1” spacer from Amazon, just a basic aluminum puck for ‘68-‘72 A body’s.