72 rear end how much can it be shortened

Discussion in 'Got gears?' started by ceas350, Oct 25, 2017.

  1. ceas350

    ceas350 "THE BURNER"

    wanting a wheel with more the 5.5" backspace. Was wondering how much could the rear be shortened before hitting the frame or relocating the shock mounts? Trying to figure how much wheel lip it would gain.thanks!
     
  2. badbuik

    badbuik Well-Known Member

    That doesn't make sense, "wanting More backspace" means the rearend would be longer........And wheels with more backspacing can be a problem clearing brake rotors, if discs... Measure what you have now, between tire and frame rail, tire and inner quarter, and wheel back spacing, then figure out what rim width & back spacing will get you where you think you wanna be... Wider rim, with more back spacing, will move the tire closer to the quarter and the frame rails....
     
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    It also matters what car and year this 72 rear end is going into, or in.
     
  4. BrianTrick

    BrianTrick Brian Trick

    With a 72 8.5" 10-bolt,for example,the maximum backspacing,with a 15" rim,is 5.5". Any deeper and the bead area of the rim will hit the shock stud. You could move the shock inboard,but if this same 72 8.5" 10-bolt is under a 68-72 A-body,the sidewall of the tire will end up rubbing on the frame,so 5.5" backspace is really your maximum backspace under an unmodified chassis.
    If this rear is under a G-body,then that is a different story. I think you can go 6.5",as long as you move the shock mount.
     
  5. ceas350

    ceas350 "THE BURNER"

    Less backspace... Hence the title of the thread. Excuse me for the typo.
     
  6. ceas350

    ceas350 "THE BURNER"

    Thanks Larry. It's my 72 lark.
     
  7. ceas350

    ceas350 "THE BURNER"


    Sorry I meant to say less backspace. Looking for the deep dish wheel look.
     
  8. ceas350

    ceas350 "THE BURNER"

    Thoughts are still a 10" wheel just more then 5.5 backspace. Maybe like 7 plus. Idk
     
  9. hugger

    hugger Well-Known Member

    rps20161118_211547.jpg If you wanting to shorten the rear that means you will have less backspace, I narrowed mine 2in each side to be able to run a 3.5 backspace 10in wheel, only reason to run more backspace like the late model Camaro wheels would need would require a longer rear end

    With the 3.5in backspace I had a 6.5 deep dish wheel
     
  10. ceas350

    ceas350 "THE BURNER"

    Thanks man! Been a long couple weeks. Ment 7" lip. I appreciate you guys.
     
  11. hugger

    hugger Well-Known Member

    You will need to take shock mount and move it in but that's it
     
  12. badbuik

    badbuik Well-Known Member

    On my '65 (which is another story) I run 15x10 rims with 6 3/4 backspacing, I remember that the bottom of the shock was close so I just redrilled the lower mount hole, up an inch.
    But from what I understand, this is not what you'd want.. You want a deep dish wheel (less backspacing), realize to make this happen you're looking at Narrowing the rear end housing ($300ish), buy new axles ($350ish), then you gotta buy those rims, say 15 x 10 or 15 x 12, with like 3 1/2 backspacing, whats that gonna cost, say $700...That's $1350, "approximately", it always cost MORE.....But that's "hot rodding" you be you, it's your car.....Start measuring.....
    Gary G.
     
    Last edited: Oct 26, 2017
  13. ceas350

    ceas350 "THE BURNER"

    Thanks dude! I figured I'd ask here to get a better idea of what folks have done.
     
  14. ceas350

    ceas350 "THE BURNER"

    Thanks Gary! I'll measure and look at wheel options.
    Nice looking lark!
     
  15. monzaz

    monzaz Jim

    1" is all I will remove from a stock 8.5 rear... then it just gets messy with the shock mount etc.
    Jim
    J D
     
  16. ceas350

    ceas350 "THE BURNER"

    I was wondering if changing the shock mount location would have a negative affect on handling.
     
  17. monzaz

    monzaz Jim

    Slightly yes.... but what are you doing with the car? Your not road racing etc.? correct? It is a burn out machine like most muscle cars are. Yes?
     
  18. BrianTrick

    BrianTrick Brian Trick

    The newer rears move the shock mount in anyway. It’s no different than a G-body,where they moved the shock directly behind the lower control arm.
     
  19. ceas350

    ceas350 "THE BURNER"


    It will be a cruiser that will also burn em. I'll have a couple hundred pounds of additional weight in the back if it matters. Thanks!
     
  20. ceas350

    ceas350 "THE BURNER"


    Good to know. Thanks!
     

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