largest rear tire without relocating springs or?

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elitesrock2

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Thinking about putting a set of hotchkis rear leaf springs on and I was wondering if relocating springs would screw with my suspension quality and also what is the widest tire i can run without relocating the springs?
 
On what kinda car? A bodies can run from a 235/245 up to a 325 depending on year and model.
 
elitesrock2 said:
Thinking about putting a set of hotchkis rear leaf springs on and I was wondering if relocating springs would screw with my suspension quality and also what is the widest tire i can run without relocating the springs?
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69 dart
 
I've got 275/60/15s on my 68 sedan with nothing more than a 1/2 spring offset. I'd think 255s could fit with everything stock. You just have to get the backspacing on the rims dead on.
 
Best thing to do is measure twice before ordering. It's pretty simple.

Get under the car and identify your two contact points. Usually the inner fender lip and the spring. Measure between the two. That's your potential maximum tire width. Then measure from the mounting surface of the rotor/axle (where the rim mounts) to the two contact points. This will tell you what your back space should be. And where your rim should be centered for max wheel size. Leave a minimum 1/2 between contact point and the tire. The rear axle will move back and forth under cornering.
 
When I was buying slicks for my Duster, I took rigid styrofoam and whittled a wedge shaped piece to strap to my old tires. Made it to approximate width of wanted tire. I rolled it around the wheelwell to check clearance. Gave me some confidence before I spent the coin.
 
245 without a 1/2" spring offset. Maybe a 255, but not all cars have the room, it comes down to factory body tolerances for a 255, some Darts can't fit them without rubbing.

With a 1/2" offset 275's will fit. Backspacing has to be right on. What's the width on the Dana?
 
I had Center Line 9.5" Auto Drags on the rear of my 65 Valiant. I had the MP 3/4 inch offset spring kit and 002 and 003 SS springs and I had to roll the inner lip of the wheel well up. I ran 28/11/50 15 ET Streets on it. Even with my wife in the passenger's seat and my son in the back seat and a trunk slam full of Kroger, it would only rub slightly on hard bumps. You should have more room on your car if I am not mistaken.
 
Dart's only have about 11" from the springs to the quarter lip with everything stock, give or take the production body tolerances. That's from my 71's, the '67-'69 cars can be a little tighter than that. That only leaves about 10" for tire, but because of the low wheel opening on the dart's that width has to be the section width, not the tread width. Even SS springs don't lift the wheel opening above the tops of the tire on a '67+ Dart. The section width on a 245/60/15 is 9.8", section width on a 255/60/15 is 10.2". Really you need a minimum of 3/8" to the springs and 5/8" to the quarter to keep from rubbing on a street car, so the 255's won't work on most Dart's unless you roll the quarter lips or do the 1/2" offset.
 
mopowers said:
I've got 275/60/15s on my 68 sedan with nothing more than a 1/2 spring offset. I'd think 255s could fit with everything stock. You just have to get the backspacing on the rims dead on.
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Same here..15 by 8", 4.5 back spacing..Be careful,on tire choices. All tire manufacturing companies,are quite different in "sizing" I have 275-60 -15" BFG. Drag radials. Measure &see a physical set,before you buy a damned thing..(My opine...)
 
RustyRatRod said:
I had Center Line 9.5" Auto Drags on the rear of my 65 Valiant. I had the MP 3/4 inch offset spring kit and 002 and 003 SS springs and I had to roll the inner lip of the wheel well up. I ran 28/11/50 15 ET Streets on it. Even with my wife in the passenger's seat and my son in the back seat and a trunk slam full of Kroger, it would only rub slightly on hard bumps. You should have more room on your car if I am not mistaken.
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408 mill?...
 
mopowers said:
I've got 275/60/15s on my 68 sedan with nothing more than a 1/2 spring offset. I'd think 255s could fit with everything stock. You just have to get the backspacing on the rims dead on.
Click to expand...
How close are those 275's getting to the front edge of the wheel well?
 
ValiantOne said:
What about a car set up for handling? Would the difference in handling be offset by the extra tire width?
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A 1/2" offset isn't going to do much at all. With a 3" relocation you'd probably need higher rear spring rates or a larger rear sway bar, but for a 1/2" it's not going to make a dramatic difference. Might be helpful to have an adjustable rear sway bar or shocks, as you could alter the settings slightly to make up for the offset. But you'd have to really be flogging the car to notice. The width of the tires and extra grip would have more of an effect.
 
ValiantOne said:
How close are those 275's getting to the front edge of the wheel well?
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I just went out and measured. There's 3/4" of clearance to the front wheel well on the DS and 5/8" on the PS. Gotta love factory tolerances. That's with the wheel well trim on as well. If it was close enough to rub a little, I wouldn't hesitate to slip a 1/4" thick aluminum spacer behind the front hanger. BTW- my tires are Cooper Cobras. I'm sure each manufacturer's tires are slightly different in size. My wheels have 4.75" of backspacing (custom steelie's from wheel vintiques). They'll make you a custom offset wheel for an extra $25 each.
 
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