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wheel question 15x8 backspacing and tire size 70' b-body

Posted By: seventy

wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 04:39 AM

So I am ordering 15x7 fronts and 15x8 steel rear repro wheels for a 70' charger, I have a couple questions, you guys may know the answers to and save me some trouble, thanks in advance..

First, I have the choice of 4" or 4.5" back spacing for the 15x8 (5x4.5) rears?

Next what size tires fit comfortably and look good in the b-body wells? Pics and size info would be great if you could share your experiences, thanks again..
Posted By: Stanton

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 05:08 AM

On and 8" wheel 3-1/2" backspacing is nice ... so go with the 4". 4-1/2 will set the whole combo further into the well and looks a bit goofy although 1/2" isn't all that noticeable!
Posted By: mopar346

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 05:28 AM

The wheel wells are huge, I run 10s with 3.75 BS I think, I would prefer 4.25 so 4 on an 8 would look good I think. 275 60 15s would be a good size but again, I like a wider tire. I run N50s on the 68 and old L60 sticky Mickeys on 10s on the 69.

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Posted By: mopar346

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 05:36 AM

69

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Posted By: Stanton

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 04:20 PM

Back in the day. 15 x 8 w/3-1/2 BS. L50-15 tires.

Unlike the Dodges in the previous post, these fit without jacking the back up, no rubbing through suspension travel.

Couldn't afford the fronts yet!

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Posted By: mopar346

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 04:41 PM

Neither of those cars are jack up by artificial means, both have the orignal 440/hemi suspension although the 68 has an extra leaf added to the stack back in the day. Neither scrubb even in off camber situations. The back space is the key, one of the reasons I said I would prefer 4.25 over the 3.75s. The rake is due to not having enough height in either the tortion bars and I probably give up an inch just in the front tire height compared to the rear.
Posted By: skicker

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/24/16 11:54 PM

I'd do the 4.5 with an 8" wheel
Mine are 5.5 back on a 9.5 wheel. Just in 17's...

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Posted By: Tommy D

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/26/16 12:02 AM

8" wheel with 4.5" back-spacing works great on Plymouth b-bodies. Be careful as Dodge (Super Bees for sure) have a slightly larger wheel well. I can run 275-60-15 tires with no rubbing issues at all. I have photos, but can't seem to post them. I can fit an entire finger between the back of the tire and the leaf spring, as well as on the outter lip of the fender. This is for a '69 Road Runner. I'm guessing the '70 is similar, if not exact.

As an fyi...lots of the stock eliminator guys and fast street racers go with a 15 x 10 x 5.5" back-spacing. They use the same tires. It gives a different contact patch, and an entirely different look.
Posted By: tex013

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/26/16 12:20 AM

I am with TommyD . With my 68 Satellite I have 15x8 with 4.5"BS , fit fine with 275/60R15 . Though I now use 255/70R15 on the street . With 8" wide 4"BS and 275's with 4 guys in car I had to roll fender lip due to rubbing . I also have 15x8.5 with 3 7/8BS , with MT 28x10.5 pro bracket radials it gets a very slight rub up in the wheel well outside , this is racing .
10" need 5.5"BS , a couple friends have this on their Plymouths with 295/50R15 , but there is sometimes a slight rub mostly inner wheel well .
The Coronet does fit a 30" tyre easier .


Tex
Posted By: forphorty

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/26/16 02:08 AM

8 inch, 4.5 bp and 275/60 on my 68 Sat
Posted By: mopar346

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/26/16 03:58 AM

Originally Posted By skicker
I'd do the 4.5 with an 8" wheel
Mine are 5.5 back on a 9.5 wheel. Just in 17's...


Are your springs moved in any? I have a set of 5.25 BS 10s that I cant use on anything cause it hits the springs when running the lugs down. They do have a wide cross section tire on them though.
Posted By: skicker

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/26/16 03:33 PM

They're not moved in at all.
SS springs moved back 3/4" with 1 1/2" lowering blocks. The tread is 9.5 and I think the section width is about 12".
Posted By: mopar346

Re: wheel question 15x8 backspacing and tire size 70' b-body - 02/27/16 04:32 AM

Gotcha the cross section on the ones I have with the 5.25 back space is 13 and change.
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