Macadoo

Okay folks, I finished my front end rebuild and the ride height stayed the same, which is good. But I think I'm over the 70's jacked-up look and would like to get the rear end back down to stock height. I found my old thread about the rear springs and looked up these Moog 5399 springs that are in there now and the installed height is supposed to be 9 inches. But I just went out and measured (with the shocks still bolted up) and got 11.5 inches including the rubber isolator. No wonder it's riding so high! I want to get back to the before picture. What do you guys think? The Moog 5379 (8.5 inches) or the 5409 (7.5 inches)?

Macadoo

Oh! But here's the thing; that before picture had the worn out springs with the helper shocks (coil overs?). When I removed the rear shocks, the bumper just about hit the ground. So I don't actually know what a stock height would look like. But I really like the look of the before pic.

oldcutlass

Nm my last statement edited out about the old springs as we posted the same time.

Fun71

Here's some spring data that I have from an online MOOG catalog:

Spring #... Installed Height.... Load (lbs)...Spring Rate (Lbs/in.)...Free Height... Application
5379 ...............9 .......................698 ...................121 ........................14.77 ........Town sedan except F-85 and Holiday sedan except Cutlass Supreme
5409 ..............7.5 .....................847 ...................140 ........................13.44 .........All 442
5401...............7.5......................727... ................128.........................13.15. ..........2 Door coupe & convertible

I like the 5409 for the lower stance and higher spring rate for better handling.

Yellowstatue

The stock height is recorded in the CSM.

Fun71

Thanks for mentioning that. I found the CSM page online a while back and have posted in in various threads, so here it is again.




My car has 5536 up front and PST "442" springs in back that I think are close to the Moog 5409. I measured the ride height a while back and got the following. I don't have factory size tires, though, they are 245-60-15s all around:
Front = 8 1/2"
Rear = 9 3/8"

https://classicoldsmobile.com/forums...-height-73619/

Macadoo

Thanks fellas, I appreciate it. I think I should unhook the shocks and measure again. Doesn't make sense but just to be sure. And I guess I'm looking for experience with certain springs, such as Kenneth posted. I don't trust published values anymore. Ken, do you have any side shots of your car handy? And are you using the thick rubber isolators?

Fun71

This is with the old 14x7 wheels and 245-60-14 tires:







This is with the new 15x7 wheels and 245-60-15 tires:

Macadoo

Thanks dude. That looks about right. What are PST springs?
You car looks immaculate!

Fun71

Performance Suspension Technology

https://p-s-t.com/

Macadoo

Whoa, pricey.