I have found the widest wheel/tire combo you can put on a third gen. Many pics

[73TXRallye440]

If you do it right and move the springs in like they should be you could have even a wider tire yet!.

what do you mean 'where they should be'?

[73chargers4404]

im going  with 16x8 torque thrust on my 73 amarican racing rims web sight said they would fit but im goin with a lower profile tire so i guess it = about the same

[Foreman72]

hmmm...some of those pics from the rears suggest no room for error or any "unforeseen circumstances" you kno...it just kinda freaks me out...i think i'll get a bit lower profile tires...maybe an inch smaller rims in width...i dunno...we'll see what my suspension warrants...just scares me how close it is to the rear leaves...but if your saying you got no issues then thats pretty sick man...thanks for the inspiration...

[wordslikebullets]

This is just what i have been looking for...  I have searched high and low and now this.  You have taken the work out so now I can just order what i need and then post some pics thanks to you guys.

[badass]

how about 15x10 5in back space ? 3rd gen stock HDsuspension would like cheeter slicks for saturday night any recomendations?

[Paul G]

how about 15x10 5in back space ? 3rd gen stock HDsuspension would like cheeter slicks for saturday night any recomendations?

5" backspace would put the tire too close to the wheel lip. It would most likely rub the fender. 5 1/4" would be the best choice if it is offered in the wheel you are choosing, even then it depends on how well your axle is centered under the car.

[defiance]

So does anyone know how much extra clearance the shackle relocation kits give?  Looking at the kit, it should add at least another inch clearance to the spring; my guess is the inner wheel well actually becomes the limit.  Either way, my thought is that with the spring relo kit I'm looking at probably 6" to 6.5" being the limit on back spacing.  Can anyone who has a spring relocation kit confirm that I'm on the right track?  I'm using a dana that I converted myself, but I built it exactly to stock specs, and I'll be sure it's dead center.  Since it's not a common wheel size, I'm guessing the option to return isn't going to be available

What I'm thinking is probably my best shot is a 17x10, 6" backspace, with 285/40 zr17 - That puts the diameter right at 26 (I have a speedo gear for that), and a section width of 11.22" ... For comparison, the 315/60r15 referenced earlier in the thread has a section width of 12.4", so I'm actually almost a half inch narrower by going with the larger diameter rim and slightly narrower tread width.  (sizing based on: http://www.1010tires.com/TireSizeCalculator.asp )

Does this all sound like I'm on the right track?

[Paul G]

Defiance,
The shackle kit only moves the rear portion of the spring inward. To do it right the spring perches on the axle need to be moved inward, then the problem is moving the front spring mount inward. On the 73 I did not see any way to easily move the front spring mount in. The wheel house is plenty big enough, the spring is the limiting factor.

[defiance]

Maybe we're talking about different kits?  I got this one a while back from doctor diff - it includes an offset bracket for each side of the front and offset hangars for the back.  See the pics below to see what I mean.  They both measure just a bit over an inch apart from factory stuff.  For the axle, I converted a dana, so I've just waited to attach the axle spring perches until the springs are moved and I've measured it

[defiance]

So I take it nobody else has doctordiff's spring relocation kit?  I guess that makes sense; Looking at his new site, spring reloc kit for the 3rd gen b-bodies doesn't appear to be available anymore.  Shame, it really looks like a high-quality piece...  I just looked up an old version of doctordiff's site on the internet archive, and it looks like it was only available for 71/72 chargers - maybe the 73 has a slightly different front perch?  I hope the spacing on the wheels/tires isn't different as well!

Looking at it, though, it's definitely just over an inch shift inward on both sides (about 1-1/8" on the back, front's hard to tell exactly but definitely just a bit over an inch).  Just to be sure, the rear end on the car now (same width exactly as the new one; I used it as a template when I cut the rear down) has 8" wheels, 3-1/2" backspacing, 235/60 r15 tires.  It measures almost exactly 2" space between the 'fattest' part of the tire and the spring right now.  The 285/40 r17 tires I'm looking at are exactly 2" wider section width (9.25 vs 11.22), so 5-1/2" backspacing would definitely rub the spring in it's current location.  If I move the spring over 1-1/8", then back the backspacing up 3/4", that should leave 3/8" clearance between tire and spring.  Well, plus the fact that the 17" tire with shorter sidewall should have slightly less bulge, so probably more than that, but worst case scenario is 3/8" clearance...  and the tire will actually end up tucked more than it is stock.  Hm....  Based on that, I could actually go for 10.5", which are really common for mustang cobras.  Those have 6.75" backspacing instead of the 6.25" I think I need... 

Is a 1/2" spacer too much? 

(trying to find some way to get maximum tire without having to custom-order wheels )

[kamkuda]

So I take it nobody else has doctordiff's spring relocation kit? 

I use it on my Cuda.  Allowed me to use a slightly shorter rear end and have the rims fit better

[defiance]

Ok, sat out in the garage for a couple hours this afternoon with a tape measure, straight edge, level, notepad & pen, and spec sheet on the rear end.  I'm REALLY confident in these measurements at this point

Fender-to-fender width on the 72 (and 71 I'd feel safe to assume) is 74-1/2".  The tires that are on my car right now round out to 74-1/2" bulge-to-bulge, and still clear the fenders by at least 3/4" at any point with the suspension as it is factory.  If the ride is lowered or taller tires are used, more clearance would be needed, but I think that's a safe outer limit for normal tire heights.  Having said that, I know the 73-74 models have slightly different fender shape, so I dunno if they're more, less, or similar.

The specs show the leaf springs centered at 48.3 inches, and they're 2.5 inches wide, so the outer edges should be 49.55 inches apart.  This measured dead on.

Stock rear end width is shown at 63" from rim mounting surface to mounting surface.  Again, this measured dead on.

One thing I found on mine is that the stock perches are not well centered.  This confused the crap out of me because the first thing I measured was the inner tire to spring clearance, and it was almost dead equal...  but I kept doing math base on the assumption that the back spacing I measured (on one side) was the same on both sides, and it kept coming out wrong.  Turns out someone bought one wheel with 1/2" more backspace than the other to get them equal in the wheel wells     Not a biggie on mine since I'll be putting my own perches on the new rear, but it's worth mentioning.


So with all that said, there's room for 311 millimeters of tire if you put it against the spring and fender!   Obviously not the optimal solution, but anyway, with 3/4" spring clearance you could probably fit 285mm wide tires (can you get those?), you'd just need almost exactly the right backspacing, you'd need your rear to be nicely centered (or compensate like the prior owner did with my car )  and you'd need it on a narrow enough rim that there's nearly no tire bulge (or a 275 with 10mm or so of bulge, so on & so forth).  If I'm doing my math right, perfectly centered for stock would be .25"-.5" (6-13mm) offset (4.25"-4.5" backspacing for an 8" wheel). 

Then according to my old emails on the doctordiff spring relocation (which may still be available for 3rd gen b-bodies), it adds 1-1/8" extra spring clearance.  That fits with my measurements of the kit.  That translates to nearly 30mm of extra tire room and a new offset of 1-3/8" - 1-5/8" (35-42mm).  So now 315's aren't going to be an easy fit, but they're in the realm of the possible with just the right offset.  1-3/8" - 1-5/8" offset on a 10" wheel is 6-3/8" - 6-5/8" backspacing, or 6-5/8" - 6-7/8" on a 10.5" wheel.  Meaning, it might actually need even less than a 1/2" spacer (or maybe even be ok without a spacer at all) to make the cobra 10.5" wheels work.

So, at this point I plan to order a set of torq-thrust M 10.5 cobra wheels for the back (black with polished lip), 8's for the front, 315-35 ZR 17 tires for the rear, and 235/50 zr 17 tires for the front. 



I'll let you know how it goes

[defiance]

Just ordered my wheels and tires, should be here around Monday or so

Quick summary of what I'm trying.  first, the measurements I've got from the rear:

63" stock hub mounting surface
74.5" confirmed safe tire outer limit (outside edge of current tires, which clear fender fine)

47.3" spring perch center-to-center
49.8" spring outer edge to outer edge
limiting widths: 49.8 - 63 - 74.5
tire space: (0 - 6.6 - 12.35)

45.05" spring perch center-to-center (with relocation kit)
47.55" spring outer edge to outer edge (with relocation kit)
limiting widths: 47.55 - 63 - 74.5 (with relocation kit)
tire space: (0 - 7.725 - 13.475) (with relocation kit)




So for the rear, the wheels I've gotten are 17"x10.5"  black torq thrust M wheels -
http://www.streetortrack.com/Torq-Thrust-M-Black-with-Shelby-cap-17x10.5-pr-22584.html
and 315/35/ZR17 tires - http://www.tirerack.com/tires/tires.jsp?tireMake=Sumitomo&tireModel=HTR+Z&partnum=135ZR7HTRZ&vehicleSearch=false&fromCompare1=yes&place=3

The wheels are +28mm offset and the tires have a section width of 12.6" on an 11" rim (so probably 12.4" on a 10.5" rim).  That puts the actual *tire* backspacing at 7.3", which is WAY too much for stock spring location, and even too much for the relocated kits (0.2 - 0.325" clearance from spring to tire).  However, the front space is only 5.1" (5.75" is available, based on current tires), so adding a 1/2" spacer puts us at .7-.835" tire-spring clearance and still .15" more fender clearance than right now.

Theoretically

I'll get it all put together and get pics ASAP


Anyway, for the front I'm not doing anything complicated, just taking the original post suggestion and adding a 1/4" spacer for a bit of breathing room.  Since I'm a couple inches larger in diameter I may not need the spacer anyway, and side-to-side fluctuation of the rim shouldn't be nearly as much of a concern as it is for the tires, but I ordered the spacers anyway just in case.  Wheels are the same as above, but 8" width with 0mm offset - http://www.streetortrack.com/Torq-Thrust-M-Black-with-Shelby-cap-17x8-pr-22578.html
and tires are the same type, but 245/45zr17 - http://www.tirerack.com/tires/tires.jsp?tireMake=Sumitomo&tireModel=HTR+Z&partnum=445WR7HTRZ&vehicleSearch=false&fromCompare1=yes&place=0

Can't wait 'til Monday!!!


BTW ---
Doctordiff does still show the reloc kits on his site - www.doctordiff.com - you just have to go to the "for sale" page instead of the products page.  "DoctorDiff '71-'74 B-body 1 1/4″ offset spring hanger/shackle kit for standard springs $185"

[AKcharger]

So...how did it all work out???

[defiance]

Worked great -
http://www.dodgecharger.com/forum/index.php/topic,21376.msg644505.html#msg644505

Time warping back I might have been a bit more demanding on the fronts (little bit wider would be nice), but no biggie - and maybe a little more sidewall.  But I'm still quite happy with it

[ultanium]

Thanks to the OP and others in this thread, I special ordered 15x10 rears with 5.25 backspace, and 15x8 fronts with 4.25 backspace for my '72. The fronts seem to fit fine, but the back was another story. I went with 295/50's & its like the rearend is offset toward the passenger side or something. Drivers side has about 2" clearance to the lip of the fender, but the passenger is ON the lip. Help!!!

[Foreman72]

Thanks to the OP and others in this thread, I special ordered 15x10 rears with 5.25 backspace, and 15x8 fronts with 4.25 backspace for my '72. The fronts seem to fit fine, but the back was another story. I went with 295/50's & its like the rearend is offset toward the passenger side or something. Drivers side has about 2" clearance to the lip of the fender, but the passenger is ON the lip. Help!!!

do you have a spring relo kit on there?

[ultanium]

No sir, bone stock. I did order some high lift springs today, and I have been told that lots of Mopars have misaligned rears. Question is, how does a person align it? Did they weld the perches in the wrong place?

[Foreman72]

No sir, bone stock. I did order some high lift springs today, and I have been told that lots of Mopars have misaligned rears. Question is, how does a person align it? Did they weld the perches in the wrong place?

May i suggest a spring relo kit...it'll move the springs in 3" per side giving you more clearance...

http://www.jimsautoparts.com/mopar_performance_steering_and_suspension.htm

[ultanium]

Thanks Eric, but my issue is fender lip clearance & only on the passenger side. Paul was right on the money with offset and size, but my rear isn't right. Even if I relocate the springs, I will still have an offset axle & have to order 2 more wheels with deeper backspace. :-(

[Foreman72]

Thanks Eric, but my issue is fender lip clearance & only on the passenger side. Paul was right on the money with offset and size, but my rear isn't right. Even if I relocate the springs, I will still have an offset axle & have to order 2 more wheels with deeper backspace. :-(

ah i see...well 2in seems fixable...can you loosen the u bolts and do some wiggling? 

[AKcharger]

I can tell you with 100% certinty that a 15x10 (4.5 B/S) will not work with with ANY tire combo. The tire place I went to promised they would. We 1st tried 275x60R15's, that didn't work. The he said for sure the ones below would work 255x60R15's...nope still stuck out and rubed on bumps (plus looked wierd) so settled on 15x8's (4 inch backspace) and went back to the 275's. They fit but it's by a chipmunk hair! I think it's a winner (3rd photo)

[Foreman72]

AK that looks incredible!! thats exactly what i want mine to look like...is that stock suspension?

[AKcharger]

Yup, I did replace the rear spring so it's sitting up perhaps a bit higher than many. My set up is 22570R15's on the front on 15x7's and 275R15's on the back on 8's. I really really wanted to go 10's but only way I could see to do that is have at least a 6 inch off set.

Thanks for the kind words...sorry to hijack the thread definace

[Foreman72]

Yup, I did replace the rear spring so it's sitting up perhaps a bit higher than many. My set up is 22570R15's on the front on 17x7's and 275R15's on the back on 8's. I really really wanted to go 10's but only way I could see to do that is have at least a 6 inch off set.

Thanks for the kind words...sorry to hijack the thread definace

17x7's??

EDIT: o i see the tire sizes now...you must have just typed it wrong...its all good