Widest Rear Tire With Factory 12 Bolt?
 

I have the rear lowered 6 inches. I have the factory 1970 12 bolt (C Clip elminator) I am going to mini-tub the girl. What is the widest rear tire I can go with? Also what backspace would I need? I'm jammed up here on this boys! Some pics would be helpful too. Ooo factory springs and trailing arms. Thanks!

Re: Widest Rear Tire With Factory 12 Bolt?
 

I asked this, and ended up having to just go and measure; are you asking for the widest tire on a normal rim, or the widest rim AND tire you can stuff in there?

If you want to go as wide as you can, you'll need to have custom wheels made or ordered.
I squeezed a 15x12 with a M/T drag radial in 325. Assuming the 12 bolt is stock width, that will be about the biggest you can go (a slightly larger diameter rim might get you a tiny bit more width inside, but not much)... it requires about an 8.5" backspacing, which is deeper than some companies will do, although you can get them. It makes rear brakes a pain though, depending on the rim size (I run 15s) you may have to modify your brakes.

http://i112.photobucket.com/albums/n...y/DSC_0392.jpg

Re: Widest Rear Tire With Factory 12 Bolt?
 

We run a 31x18.5" hoosier on a minitub and smaller diameter springs.

http://67-72chevytrucks.com/vboard/a...1&d=1305311294
http://67-72chevytrucks.com/vboard/a...1&d=1305311294

Re: Widest Rear Tire With Factory 12 Bolt?
 

Prostreet68 what backspace are you runnin? I was wondering if 15x12 with 7.5 backspace and 325 tire would fit?

Re: Widest Rear Tire With Factory 12 Bolt?
 

Not sure if your slightly newer fleetsides are wider or not. I've got eh trailing arm suspension w/ jeep springs which are a tad wider.

If I would have gone with a 7.5" bs, the tire would rub into the outside of the fender.

Re: Widest Rear Tire With Factory 12 Bolt?
 

315/60/15 MT drag radial on 15x10 with 5" bs on stock width 12 bolt. No tubbing needed.

Re: Widest Rear Tire With Factory 12 Bolt?
 

We're running a non tapered, we've alway assumed they were Jeep springs.


And we're running 8.75inches of backspacing.

Re: Widest Rear Tire With Factory 12 Bolt?
 

I had 12.5 wide sportsman pro's on this old 71 with an off the shelf Centerline Telestar wheel.http://i129.photobucket.com/albums/p.../s131007-2.jpg
http://i129.photobucket.com/albums/p.../s131010-2.jpg

This truck was not that low you would need a little more back spacing but not a ton.

Re: Widest Rear Tire With Factory 12 Bolt?
 

Here is link to a pic i posted last year for some one asking the same kind of question. I was lazy and didn't want to find the pic and upload again lol
14 or 14.5 wide wheels with 15 inch wide tires and all stock susp. and stock width rearend that is what it had when i bought it.
http://67-72chevytrucks.com/vboard/s...12&postcount=8

Re: Widest Rear Tire With Factory 12 Bolt?
 

I have a 15x12 6"back space will it work on a 1965 chevy truck ,what is the lest back space u can have with a15x12 wheel
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Re: Widest Rear Tire With Factory 12 Bolt?
 

Is your truck a stepside or a fleetside?

Re: Widest Rear Tire With Factory 12 Bolt?
 

Fleetside
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Re: Widest Rear Tire With Factory 12 Bolt?
 

Welcome to the forum

Re: Widest Rear Tire With Factory 12 Bolt?
 

What Year?

Re: Widest Rear Tire With Factory 12 Bolt?
 

:waah:Posted via Mobile Device

Re: Widest Rear Tire With Factory 12 Bolt?
 

My plan is replacing the 12 bolt with a stronger rear (Dana 60 or 9.5" 14 bolt) and narrow it by 1.5-2" per side w/mini tubs and 15x12's...then 315/60-15's will fit easily.

but for now...its factory 12 bolt with new Eaton posi and 3.73 gears
they're 15x10", 4.5"b.s., with MT ET Street radials in 315/60-15
http://www.lsxtrucks.com/gallery/alb...l_IMG_2397.JPG

http://www.lsxtrucks.com/gallery/alb...l_IMG_2399.JPG

Re: Widest Rear Tire With Factory 12 Bolt?
 

Is your 12 bolt the original 62" wide or is it the wider '63.5" width used from late '70 on up? Are you willing to widen the inner wheel wells? What size tire are you wanting to run?

Re: Widest Rear Tire With Factory 12 Bolt?
 

15"29x15.5 , later 70&up
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Re: Widest Rear Tire With Factory 12 Bolt?
 

Did you have to narrow the frame?
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Re: Widest Rear Tire With Factory 12 Bolt?
 

Where u get dose rear ralley wheels
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Re: Widest Rear Tire With Factory 12 Bolt?
 

Nope. Cut the bed back to the frame and run straight spring instead of a factory style.beehive.

Widened factory wheels.
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Re: Widest Rear Tire With Factory 12 Bolt?
 

My rear tires are a 29/15.50 15 sportsman or a 31 10.5w on a custom Holeshot 16" rim with a 10" backspace. I ordered a new set of factoy rear wheel tubs and welded them to my old ones. My frame has not been moved and I ran the factory style spring with this setup.

Re: Widest Rear Tire With Factory 12 Bolt?
 

do you guys think ill be able to run 295/50/15 with a 5.5 bs, on a 69 short bed fleetside (factory tubs) and have everything clear?

Re: Widest Rear Tire With Factory 12 Bolt?
 

Re: Widest Rear Tire With Factory 12 Bolt?
 

factory 12bolt and 15 by 10 rims with either a 5 or a 5.5 bs
i seem to remember that there is around 12 or 13 in the factory tubs. the truck is in the shop being painted right now and i dont have it here to measure