Rear Spring Recommendation

Discussion in 'The whoa and the sway.' started by LARRY70GS, Jun 10, 2021.

  1. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    With the N25 conversion I did, the pipes ended up very close to the springs. Not even enough room for the heat shields. It is what it is. I have the HR bar in the back, so I don't need air bags for traction.

    I was able to shim the current springs up, so I don't have a problem with tire clearance at present, I just wanted to see if I could find a set of the obsolete 5399 springs. I requested a quote from Eaton. They recommended their part number MC1245 +2. They are 245.00/pr + 35.00 shipping. Those are the springs Kevin used in post #33. They might be a bit too much lift.

  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    So at present I was able to shim up the new 5385 springs to the point where I think I will leave it for now. The car sits the way I want it to and I have enough clearance on the driver's side to clear the P275/60R-15. Before the shim, I could barely get my fingers in to the first knuckle. Now, I can get my hand in there. I have the car sitting right where I like it. It could still use the increased back space on the driver's side, but at least now, it doesn't rub on bumps. I have new wheels on back order from Wheel Vintiques. Hopefully, sometime in August. For now, I'll leave it.

    SpringShim1.jpg SpringShim2.jpg SpringShim3.jpg SpringShim4.jpg
  3. Cutlass

    Cutlass Platinum Level Contributor

    Larry, I measured my GS with 26 1/2 right and 26 left in the back. I run 295/50-15 on 8" rims with 4.5" backspace and no rub at all. So I have about 1" less ride hight in the back, but to me it looks like my ride has a little bit more stance than yours. It looks like your car stands pretty high in the front (at least compared to mine). Unfortunately I do not know which springs are installed, as I bought the car that way (except for the additional isolators I installed when I swapped the axle).
    70skylark350 likes this.
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    You have shorter tires. I have P255/60R-15 up front (27"), and P275/60R-15 (28") out back. The right side of my car is a bit higher, both front and rear. Out back, the left side is just under 27", right side is 27 1/2". Front, the left side is 26 1/2", right side is 27". I am happy with the way the car sits presently. The rear left 275 no longer rubs. The new wheels with 1/2" more back spacing will give me even room.
  5. Cutlass

    Cutlass Platinum Level Contributor

    Glad it worked out to your liking.
    Here is the difference. I measured up front 25 5/8" left and 25 5/8" right.
    I believe the tires do not make that huge difference. For the front it is just about 1/4", for the rear tires it is about 1/2" difference. Of course in the end everything adds up, as little as it might be.
  6. Max Damage

    Max Damage I'm Working on it!

    The car looks great! In the photo with your hand, is that a crack in the tire between the sidewall and the tread? It scares me a bit.
  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    No crack, although I can see why you might think so. That is just the way the tire is molded.
    Max Damage likes this.
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    My car sits a bit high in the front. I do prefer that.
  9. Cutlass

    Cutlass Platinum Level Contributor

    That is where I might end up as well, once the headers are installed. Form follows function :).
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yup, my MT headers are virtually unscathed.:)

    Last edited: Jun 27, 2021
    FireRedGS455 likes this.
  11. Atbb

    Atbb Well-Known Member

    Hi, just had new springs installed, 455 non-AC car, automatic, 245/60/15 on 15x7 all around. Maybe this might help somebody decide what to choose or not. Bushings and all new.
    Moog 5379 and 5536


    Attached Files:

    TimR and FireRedGS455 like this.
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    That looks great. I was considering the 5379, but they are quite a bit softer than the stock 5385's (122/168).
  13. Atbb

    Atbb Well-Known Member

    Great you like it...rides really good, but then I`m evolving from totally shot bushings and worn springs, so mabye I`m not 100% objective.

    Ride quality is great though. What I realized is that it`s up in the back but can sink in quite a bit. Search for "International connection |" , it`s a photo taken with 2 guys in the back (front is still the old springs) really sinks in under load.

    But while driving you get the feeling of a firm ride, I like it a lot, would recommend that setup.

  14. Jim Weise

    Jim Weise EFI/DIS 482


    Car looks great.. but come on, any street tire.. who are you kidding???

    I would bet the car is down on one side, because of the front springs... could be as simple as they are not oriented in the frame the same.. check that..

    Every GS/Skylark I ever had to fix for this was the front springs.. I think we did 4 or 5 where that was the owners complaint.

  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    You are right Jim, it is higher in the front right as well. I'll add it to the list. Yeah, I know, I need to run the drag radials all the time.:D The street tires keep me from getting myself into trouble though.
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Just got back from Beaver Springs Raceway. While I was there, I saw Paul Cassidy (Buickwagon). He says to me, "Larry, I have a box for you". I say, "really"? He says yeah, you know those Moog 5399 springs you were looking for? He gave them to me, wouldn't take any money either.:) Thanks Paul!

    Last edited: Jul 31, 2021
    12lives and 73 Stage-1 like this.
  17. Cutlass

    Cutlass Platinum Level Contributor

    Very cool and very generous from Paul. Another proof for how nice the community here is.
    Curious to see your car with the new springs installed.
    12lives likes this.
  18. Buickwagon

    Buickwagon Wagon's Rule!

    You're welcome Larry. Just happy to be able to help. I hope they work out for you!
    Cutlass and 12lives like this.

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