Guys who are Mini-Tubbed please read...

[Rodzilla]

I'm mini tubbing my 71 Demon and will be running a 10" rim and probably a 28" Mickey Thompson ET Street, or a Hoosier QTP in a 29". Both have section width of close to 13.5". My question is what backspacing to get that tire to tuck inside without rubbing the inside of fender or the frame rails. I have a Bill Reilly Street-Lynx triangulated 4 link coming with the shorter QA1 coilovers, so it will sit pretty low. So tire centering in the wheel well will be crucial. I would like to have tires/rims ready for Resto shop when rear is being installed, instead of installing 4 link then measuring and then ordering my rollers. Of course I will go that route if I can't find someone with concrete numbers.
I am running a stock A-body 8 3/4" with wilwood 12.19" Disks in the back. I think I will have body shop roll the inside lip of the fender for added clearance. I was measuring on a buddys duster tonght and it looks like from fender to frame rail is 14", lower rods with be attached to frame rail by the way. And I think with a 10" rim I should run 6.5" of backspacing to get it centered in the wheel well. Sound right to anyone running a similar setup? Any thoughts or ideas is appreciated. My suspension will arrive in a couple of weeks and my car heads for the body shop just before that, so trying to figure this out and get some rolling gear ordered as well.

Thanks Guys

 

[project360]

im running a 325x50x15 which is 28x13.5 on a 15x10 and a 6.5 back space with a little finder trim also. however on my Scamp from frame to fender trim is 15 in. (we cut .25 off the fender instead of rolling it.

 

[zhandfull]

Here is my Demon stock A body rear with no mini tubs. leafs moved in 3/4" each side wilwood brakes. Its been awhile but I'm pretty sure the wheels are a 5" backspacing.

My tires will rub on the outside fenders on bumps. I think 6.5" backspacing will probably be pretty good.

 

[DART340]

Its not a Demon, but on my swinger I run the 3" inset springs with 10" centerlines, 7.75 offset and 325/50/15 mt, no rubbing, no fender trimming.

 

[Brad4406]

http://www.bigblockdart.com/techpages/wheelspacing.shtml

From Big Block Dart's Tech Page. Bill has a lot of handy info on there.

I believe 6.5" backspacing should be correct. Here's why:

71 Duster, B-body width Dana, 10" wide rims w/6.5" backspacing and 3/4" spring relocation kit. They worked perfect with never a rub and the tubs were never touched. You said you are running an A-body rear which is narrower so 6.5 would tuck the wheels further inboard than what mine show. I'm betting it will be close on the inside, but should clear. You may have to take it easy on the corners though.

 

[BrianT]

I mini-tubbed and relocated the springs on my Dart with a factory A body rear end. It required a 7.5 inch back space to run a 10 inch wheel. I didn't like the look of the wheel with that much back space, so I bought a narrowed Strange 60 rear end, 4 inches on each side. That lets me run a 3.5 inch back space which I think looks a lot better.

If you're going to all the trouble to add the 4 link and mini tub, might as well narrow the housing. Just my two cents.

 

[Rodzilla]

I mini-tubbed and relocated the springs on my Dart with a factory A body rear end. It required a 7.5 inch back space to run a 10 inch wheel. I didn't like the look of the wheel with that much back space, so I bought a narrowed Strange 60 rear end, 4 inches on each side. That lets me run a 3.5 inch back space which I think looks a lot better.

If you're going to all the trouble to add the 4 link and mini tub, might as well narrow the housing. Just my two cents.

Why go thru the hassle and expense just to have a deeper dish wheel on the back. Wont bother me at all if backspacing is 6.5 or 7.5". I'm spending about $30K on this car in next 3 months and if I can save some bucks here and there, all the better.
But thanks to you and all the other guys who posted up comments and pics, much appreciated.
If anyone else cares to chime in please do. More ideas of what works the better.
Thanks.

 

[Rodzilla]

Here is my Demon stock A body rear with no mini tubs. leafs moved in 3/4" each side wilwood brakes. Its been awhile but I'm pretty sure the wheels are a 5" backspacing.

My tires will rub on the outside fenders on bumps. I think 6.5" backspacing will probably be pretty good.

What size rubber you running on front and rear of your car, I'm going to do front runners as well? I think I'm going to go with Weld S71 for wheels. 10" wheel on rear and 4" wheel on front. Of course as much backspacing as I need to tuck the wheels since my new suspension will have the car riding low. I am eventually going to go for a pro-touring look with big wheels and low pro-file tires to take full advantage of the modern suspension for cruising. But my budget isn't looking good for $5k in wheels and rubber right now. And the Welds won't go to waste anyway since I can use them for the 1/4 mile later.

 

[zhandfull]

What size rubber you running on front and rear of your car, I'm going to do front runners as well? I think I'm going to go with Weld S71 for wheels. 10" wheel on rear and 4" wheel on front. Of course as much backspacing as I need to tuck the wheels since my new suspension will have the car riding low. I am eventually going to go for a pro-touring look with big wheels and low pro-file tires to take full advantage of the modern suspension for cruising. But my budget isn't looking good for $5k in wheels and rubber right now. And the Welds won't go to waste anyway since I can use them for the 1/4 mile later.

I'm Running

15 X 4 Fronts with 28 x 7.50 M/T front runners
15 X 10 Rear with 28 X 12.50 M/T Rear tires

 

[Commando66]

My car is an early-a, but I run a 15 X 10 with 6 1/2" of backspace. There are no clearance issues with the body or suspension. However, i do run a wheel spacer to get my Weld's to clear the calipers on my Wilwood brakes.

 

[Mad Dart]

I used a B body housing and narrowed it 3.75" on each side.
Mini tub and a home brewed triangulated 4 link. 15x10 with 5.5 back space and 325/50/15 MT Streets puts it dead center on my 67 Dart. I did not roll the fender lip
at all and I got 15" in the clear after mini tub.

Since you are spending alot of $$ you should shorten the housing in my opinion. Will look funky with too much backspace.
You can see pics in the thread below.

 

[Rodzilla]

Thanks guys and nice build Mad Dart. Cammando66 I'm thinking 6.5" backspacing will be what I'll try. Worst case if I set it back to much I can ad a spacer and as far as clearing the Wilwoods, I can order the S71 Welds with different mounting pad hieghts to help clear brakes, I guess I will stay away from the low ones. Again it doesn't matter to me if I get the deep dish look in the back, its the ability to stuff big rubber with less mods. Thx.
Love the pics of all your rides, more would be great!

 

[BrianT]

I'm thinking 6.5" backspacing will be what I'll try..

Don't guess at what backspacing to use. Take careful measurements and get the right wheels the first time. Here is link to the method that I used.

http://www.bigblockdart.com/techpages/wheelspacing.shtml

I measured about 10 different times before ordering my wheels, and they fit perfect.

I just prefer the look of a deep dish wheel. If you like a more modern look, then a deep backspaced wheel will be fine. Also, the disc brake set up that I'm running recommends no more than 3.5 inches of back spacing to keep the wheel from hitting the park brake lever.

 

[Rodzilla]

Before I made this post 6.5" is what i had figured out by doing measurements. Just from reading replys I have confirmed that it will be close enough. If I find any rubbing issues a tire with less section width or a spacer can help that.
But thanks for the note about the park brake issue, I will have to check if my new wilwoods will have any issue with that. If so I might be off to get some narrowed axles after all. Cheers guys.
Thanks, I've been a Dodge guy for 25yrs but new to this forum and all the info is great. I last owned a 340 Dart Sport back thru the nineties and regretfully sold it in 2002. I wish the internet was going strong back then, would have been great to have access to everyones knowledge back then. I'll get a build thread going in a couple of weeks once the Demon heads of to the Resto Shop.
Cheers to ya.

 

[green1]

First thing, what is rear gearing? Then how tall of a tire you need.Doing this,calculate rpm at 1/4 mile. At ride height, measure inside well. Buy the tire, set it in there, on blocks, at ride height. Then figure backspace, and cry when they quote it....

 

[Rodzilla]

My rear gearing will depend on what tire will fit.