Old 01-06-2019, 11:34 PM
Slider Slider is offline
Join Date: Jan 2017
Location: Dallas, TX
Posts: 93
Default Rear sagging on 65 Tempest

Im inching closer and closer to driving my car but Im concerned that the rear is sitting way too low right now. The front fender lip to ground at top of wheel arch is 26.25 and the rear is 24. My 255/70R15 tires in the rear are barely clearing the inner fenders. Not sure how guys make 275s work. (I have 235/70/15s in the front)

My question is I can get standard AC Delco or Moog replacement spring for around $40 for the pair thru Rock Auto, or should I go with convertible (if they are different) or station wagon spring to get the rear up higher. Id prefer a level stance, if not slightly higher in the rear (by maybe 1/2 - 3/4 higher in rear)

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Old 01-07-2019, 08:50 AM
The Champ's Avatar
The Champ The Champ is offline
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Join Date: May 2002
Location: Grand Meadow, MN
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The front wheel arch is taller than the rear - so the difference in ride height is no the 2.25" that you think it is. A better measurement would be to check the ground clearance from the frame rail just in front of the rear wheel and just behind the front wheel.

That said, your rear tires are .9" taller then your front tires - so .45" more ride height in the rear based on tire size.

From the factory, these cars sat a little lower in the rear with all 4 tires the same size.

If your springs are original, it's very likely both front and rear are sagging to a point - and maybe the rears are sagging more than the front. If they are not original - and you weren't the one who replaced them - who knows what is in there. Also - if you lightened the front end (eliminating AC, aluminum intake, etc) that would have raised the front somewhat.

Without knowing for sure what you have - it's hard to say what will happen to the ride height.

Back when I restored my '64, I put all new factory spec'd springs from our host all the way around. The rear end on my GTO convertible had the factory appearance of the rear end sitting lower than I wanted as a result. I ended up contacting Coil Spring Specialties and had them build a set of custom springs with a .75" lift. Upon changing out the rear springs - that is exactly what I got.

Long story short - if your springs are older - trying a set of OE replacements might get you what you want. If you change them out and still want more - Coil Spring Specialties can make exactly what you want.


My '64 GTO Convertible
Mrs. Champ's '72 Camaro
Our '49 Caddy Limo
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I rarely agree with Chief, for very good and obvious reasons.
Old 01-07-2019, 10:31 AM
randy1966GTO randy1966GTO is online now
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Join Date: Feb 2013
Location: Rowlett, Texas
Posts: 29

Replacing the springs is a crapshoot as far as ride height goes and I elected to put the Air Lift drag bags in mine. $85 and easy to install, they are adjustable for ride quality and height and I love the results.


Old 01-07-2019, 01:39 PM
Chris65LeMans's Avatar
Chris65LeMans Chris65LeMans is offline
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Join Date: May 2013
Location: Los Angeles, CA
Posts: 1,395

Its been said on here that these cars came with a reverse rake when new

As has been said - look at the whole car. What is the current stance?

Id lean more towards cutting the front springs a bit rather than buy new rear ones. It sure would be disappointing to put new springs in and end up with the same stance.

1965 Pontiac LeMans. 440 CI, M21, 3.73 in a 12 bolt.
Old 01-07-2019, 01:41 PM
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Johnny99 Johnny99 is offline
Senior Member
Join Date: Dec 2014
Posts: 106

The below links offer quite a bit of info that should help. The forum posts include some formulas to determine the different ride heights of springs based on their specs.


Chevelle usage

Skylark usage

The last link includes the spring specs


NOT a GTO. 1965 LeMans 455
Old 11-19-2019, 01:21 PM
FrankieT/A FrankieT/A is offline
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Join Date: Jun 2011
Location: USA
Posts: 2,149

I used to use a rear spring set from a wagon, not aftermarket cargo coils. You'll end up with about an inch higher in the rear.

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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, SS 700 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars
Old 11-19-2019, 01:58 PM
66sprint6 66sprint6 is offline
Chief Ponti-yacker
Join Date: Oct 2008
Location: Toronto, ON, Canada
Posts: 723

We tried the springs from Rock Auto. Moog or AC Delco I forget which. Terrible results. We then ordered from Coil Spring Specialties and achieved excellent results. If I had known, I would have just gone to CSS in the first place.
That being said, even with the proper factory ride height, we still installed the air bags. It firmed up the ride and I can jack up the back an inch or so if I feel like it.

Old 11-19-2019, 02:23 PM
Skip Fix's Avatar
Skip Fix Skip Fix is offline
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Join Date: Dec 1999
Location: Katy,TX USA
Posts: 18,621

I got MOOG form OReilly for a Chevelle. Even new 65 GTO springs were a hair low. Especially with the 275s I used to roll it around the shop! Still has slightly saggy original front springs. Original rears were really saggy and had helper springs on the spiral shocks!

Skip Fix
1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
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Old 11-19-2019, 02:59 PM
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Stuart Stuart is offline
Join Date: Apr 2003
Location: Minneapolis
Posts: 6,899

Are you looking for whatever was the stock ride height, or what looks good? If you have a factory shop manual, there should be information in there on how to determine the correct height per factory specifications (I think it's typically done by measuring parts of the suspension and how far they are apart, but this probably varies by year and model).


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