mini tub

[DAWG 340]

i just finished mini tub my 70 duster. can any one advise me on how big of a tire i can fit in there also what type of backset on the rims. i plan to use cragers any help would be appreciated.

 

[TheGrateRonzini]

Any modifications to the rear end? Is it stock rear end? What one?

 

[DAWG 340]

it stock 8/34

 

[Locomotion]

Are leaf springs in the stock location, on 3/4' offset hangers or moved into the frame rails?

I got 9" Hoosier slicks + sidewall bulges on a 10" rim to fit nicely in the wheelwell with 3/4" offset hangers. (no mini-tubs) I don't think you'll gain much without moving the springs.

Early on I had 10.5" bias slicks with 1" more rim width on the outside but I didn't like the sidewalls sticking out even though tread with was within the fender lips. Car isn't here but I have spare mounted wheels that I can measure overall witdth (sidewall buldge) and offset with the 9" slicks..

 

[Oldmanmopar]

The biggest is 12 inch wide with a 7 1/2 back space

 

[DAWG 340]

the springs are located om the frame rails

 

[roccodart440]

i just finished mini tub my 70 duster. can any one advise me on how big of a tire i can fit in there also what type of backset on the rims. i plan to use cragers any help would be appreciated.

At least 13.1" section width, because that fits under a 69 dart and you don't have the quarter panel skirting the tire.

 

[AJ/FormS]

From a street perspective;
My stock 68 Barracuda tubs accept 325s with just the springs offset.
IIRC those are 13.6 profile on 10s , but 10s are really not wide enough.
Even my 295s on tens have to run down at 24psi for long tread-life. I got used to the rear steer and now I like it.
But, on the stock rear end location, at about 28"tall the front of the tire is getting a lil too close to the sheetmetal for my comfort, and spacers on the stock hangers are only good for maybe 3/8" more room. Some guys reshape that corner. So far, I've been getting away with the spacers.
> I'm pretty sure the Duster has the same size factory tubs. So just add
whatever the mini-tubs and springs in frame, gave you.

If it was me,
> I'd narrow the rear end cuz I like better, the deeper-dish look. and
>Cragars are pretty heavy for street, especially when you get to 10s or 12s..
> My alloy wheels weigh nearly half of what a steel Rally weighs. My back really appreciates the lighter wheels.
> FYI; 275/60-15s seemed as good as 295/50-15s, in straight line work.
But IMO, 295s are better for drifting, cuz with more sideways rubber, there is less drama and quicker/easier recoveries if/when I screw up... And 275s can be run on 8.5 wheels for lighter total weight, and can run 28psi for a long tread life and some say better street manners.

The biggest is 12 inch wide with a 7 1/2 back space

I'm thinking you mean 12" tread?
Ima thinking, that would be close to a 340profile; and, on the street, should probably be run on a minimum 11" wheel. I'm guessing.

 

[Heywodja]

I did mine on a 72 Dart which has less room than your Duster right out of the gate. I also relocated the springs to the frame rails, and I am using a stock width 8 3/4 as well.
I am running 325/50/15's on some stock cop wheels widened to 10" with a 7 5/8 backspace. They fit like a glove...

 

[roccodart440]

From a street perspective;
My stock 68 Barracuda tubs accept 325s with just the springs offset.
IIRC those are 13.6 profile on 10s , but 10s are really not wide enough.

Agreed, you really want the tire on the widest wheel possible, or you are forced to run low tire pressure and you will get more sidewall flex with a narrow wheel, wide tire combo

I run 11.25" wheels with 13.1 section width tires. Just under 2" less than the section width.

 

[RustyRatRod]

You need a tire and wheel fitment tool. There are several on the market. I have one made by Percy's. It's been discontinued, though.

 

[6PKRTSE]

Everyone else's advise is purely just a close guess. Measure your car yourself. You have many variables and +/- tolerances to consider. This way you know for yourself you can get the maximum tire under there with no issues.

 

[72bluNblu]

A '70 Duster should have close to 15" from the frame rail to the quarter lip, if it hasn't been trimmed/rolled already. So even allowing a 1/2" of clearance on the frame and quarter lip on a car with an untrimmed quarter you'd have close to 14" to work with for the section width of the tire.


The 3" relocation really makes a lot of space. 72BBswingers car had a 3" relocation and mini tub, he had 18x12's with 335/30/18's on it and said he still had some space. This is his car (was I guess, he sold it). But this is a Dart, and with nothing else changed a Duster will have an extra 1" of wheel tub space than a Dart does because of the wider quarters. So, 335's would be a piece of cake. Maybe 355's?

Backspace will be dependent on whether or not the axles have been upgraded to BBP or not and what rear brakes you're running. But a 12" wide rim should be easy. And that's without any trimming or rolling of the quarter. On my Duster, with a rolled flat quarter lip and quarter that was pushed out with the fender lip roller, I've got 16.5" from quarter to the outside of the frame rail.

 

[DAWG 340]

thanks guys this gives me a good starting point. i plan on putting the biggest tire i can get in there i am glad i waited to by rims these post give me a good direction to not waist money on the wrong rims /tires . thanks again guys.

 

[oi81b4uu812b4]

If you just tubbed it I would get some measurements to make sure a frame rail wasn't off 1/4" from the factory. That said, in a perfect world on a Duster you should have 15-1/16" clearance. I would trim your fender lips back slowly with a grinder and a flapper wheel about 1/2", it's a little pointless unless you reverse tub the outer wheel housing shape. You could run 18" DIA on the front and step up to 19" DIA in the rear to use 355/30/19. If you can find them there are 375/30/19 tires out there that will fit. As far as what back space you need on you rims, I would just measure what you got for a rear end. It's not that complicated, and give yourself a secure piece of mind.

You will be looking at a 12"-13" wide rim with a 355/30/19...