I have a 1971 Demon 8-3/4” rear with rear disc’s. The wheels are vision legends 5’s and in the rear they are 18”x9.5” 5.72”BS/+12 offset on Nitto G2 275/40R18. Are these too tight to the leaf spring? I dont see tires side flexing that much to hit the springs but wanted to know other opinions. They are pinky spaced or 1/2” from spring. Do i need a spacer or they are fine? The fronts are perfect at Front 18”x8.5” - 5.55”BS/+20 offset Nitto G2 245/40R18
Is this enough space on my rear wheels? 18” wheels
- Thread starter J.B.
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Projectile Dart
Well-Known Member
the pictures are deceiving,they almost appear to only have a few hairs of clearance but in general I would say that 1/2inch is enough if that is what you see
I would suggest to take it slow, maybe drive around the neighborhood and hit a few speed bumps and dips and take it straight home and inspect again for any signs of rubbing, then continue to step it up to freeway speeds doing the same process
I would suggest to take it slow, maybe drive around the neighborhood and hit a few speed bumps and dips and take it straight home and inspect again for any signs of rubbing, then continue to step it up to freeway speeds doing the same process
Pictures can be pretty deceptive when looking at that amount of gap. It doesn’t look like you’ve got a 1/2” there.
That said, if you do in fact have a 1/2” to the spring, that’s enough clearance. When I was running drum brakes still in the back I only had about 3/8” between my springs and the 275/35/18’s I was running and never had any issues there.
The shorter sidewalls you get with 18” rims don’t move around as much as what you usually get with a 15” rim, but also remember that the springs themselves flex and those leafs slide around on each other and can shift around a little.
That said, if you do in fact have a 1/2” to the spring, that’s enough clearance. When I was running drum brakes still in the back I only had about 3/8” between my springs and the 275/35/18’s I was running and never had any issues there.
The shorter sidewalls you get with 18” rims don’t move around as much as what you usually get with a 15” rim, but also remember that the springs themselves flex and those leafs slide around on each other and can shift around a little.
What kit are you using? Do you know how much they move the WMS out?
I used the rear disc kit Rear 1973 Dart discs kit DBK834LX, motor isnt in havent drive. It yet it free roles perfectly pushing in and out if driveway but im just concerned cause it is really really close 3/8-1/2”
Corners will be the true test. Tires flex and “twist”. Typically 1/2” is tight but okay.
Syleng1
Syleng1
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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On the street, I've run down to a quarter inch, with 325/50-15 BFG DRs on 10" wheels @24psi, with offset springs that are de-arched to nearly flat.
But; when cornering, the entire body shifts sideways on the rear shackles, and the tires rub on the inner wells, which have a static 3/8ths inch....... but amazingly not on the springs. So, on the street, I slow down, lol.
They are fine for dragracing, even down to 12 psi.
But; when cornering, the entire body shifts sideways on the rear shackles, and the tires rub on the inner wells, which have a static 3/8ths inch....... but amazingly not on the springs. So, on the street, I slow down, lol.
They are fine for dragracing, even down to 12 psi.
TrailBeast
AKA Mopars4us on Youtube
I have 1/2 an inch with 40’s on 18 inch rims with no issues.
It’s my daily driver, so it’s been tested well.
Like mentioned above the short sidewall doesn’t move much.
dano
Evil Handy Man
Just to confirm what the others have said, I have approx. 0.25" from the tire bulge to the spring with a 45 series tire and no issues.
If these were 70 up series tires and hitting the corners pretty hard I'd be worried
If these were 70 up series tires and hitting the corners pretty hard I'd be worried
Those rubber band tores won’t flex much. Amd the springs are clamp so,they aren’t moving 1/2”
The tire can hit the top of the wheelwell when the rear axle goes up or down on one side it tilts the tire then rubs. Won’t hit the spring doing that.
The tire can hit the top of the wheelwell when the rear axle goes up or down on one side it tilts the tire then rubs. Won’t hit the spring doing that.
I mounted up the 18x10 +6 last night. T his is on a stock spring location 8.25 w/drum brakes and a 3/8” spacer on each side. This equals 52.25 spacer to spacer. An A-body 8.75 is 52.625”. I’ll still need the spacer or cut my B-body housing to a 53 - 53.25” flange to flange.
The back lip touches the spring so I would still need spacers on an A-body 8.75.
Does the rear Dr. Diff 11.7” brake kit move the WMS out?
The back lip touches the spring so I would still need spacers on an A-body 8.75.
Does the rear Dr. Diff 11.7” brake kit move the WMS out?
DionR
Well-Known Member
Any rear disk kit will act like a 1/4" spacer or so, due to the slip on rotor.
Just talked to Forgeline and since I will be changing both halves they can send me the two sealed replacement shells. It's as simple as unbolting the face and making sure it's cleaned of the old sealant and prepped with alcohol, mating the three pieces, and torquing the hardware in sequence.
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So typically with an A-body 8 3/4 with stock spring locations a +12 offset is pretty close to where you need to be. The 8.25” is narrower by about a 1/2” per side. The 52 5/8” measurement you’re using is the housing width, not the WMS-WMS measurement. An A-body 8 3/4 with BBP axles is ~57 13/16 wide WMS to WMS. The SBP version is more like 57 1/8”.
With the stock spring locations and BBP axles in an A-body 8 3/4 with drums you typically get about 6” from WMS to spring. With a 1/2” offset you should be a bit better than 6.5” from WMS to spring. As Dion pointed out the disk kit will add another 1/4” or so, now you’re at 6 3/4”. Figure about 1/2” of tire clearance and a 1/2” of tire overhang, and I think that 5.75” backspace is about perfect.
May I just say those wheels are going to look killer on that car! Great color combo.
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