How much can you narrow rear axle with a mini tub kit?

[lancef53]

Working on a 73 Challenger, installing a level 3 USCT kit in prep for a gen 3 hemi swap. Currently planning on a 9" rear to replace the 7 1/4 in the car. With the couple inches of extra room per side, is it best to go with a 4" or so narrower axle? The plan is to use a 4 link/coil over setup in place of leaf springs. I haven't sourced wheels/tires yet, so I still have flexibility.
Thanks for any advice!

 

[Steve340]

It would pay to get the wheels/tyres and adjust the rear axle width to work with the wheels and suspension set up.

 

[6PKRTSE]

Yes, correct. I bought the wheels and tires first that I knew would fit in the mini tub that I did first on my blue 70 Challenger. Then we measured and cut with dimensions that I was able to figure out from the Strange Engineering axle flanges and rotor thicknesses. I don't recall how much I cut off each end, but it wasn't much since my Dana 60 axle originally started off as a narrower 1 ton dually axle.

 

[lancef53]

Thanks for the replies. Is the Dana 60 from a pickup the same center/tubes as what was in the cars?

I was just curious if people normally narrowed up the rears when they do the mini tub kit. I prefer the look with a little more dish on the outside, compared to the newer vehicle setups.

 

[HPP]

If you are doing a pro street layout, it really depends on the offset you want to run on the wheels to determine how wide the axle needs to be.

I've done some mental gymnastics around wider front track width to play with scrub radius geometry which would also require a wider rear track in order to maintain the square tire size I'm currently pursuing. That's a whole different animal that what your after.

 

[6PKRTSE]

Thanks for the replies. Is the Dana 60 from a pickup the same center/tubes as what was in the cars?

I was just curious if people normally narrowed up the rears when they do the mini tub kit. I prefer the look with a little more dish on the outside, compared to the newer vehicle setups.

My truck Dana does have extra thick axle tubes. They are thicker than car Dana's. I think they were like 3/8" wall or slightly over. I agree with depth on wheels. I went with 15"x12" with a 6" back space.

 

[lancef53]

If you are doing a pro street layout, it really depends on the offset you want to run on the wheels to determine how wide the axle needs to be.

I've done some mental gymnastics around wider front track width to play with scrub radius geometry which would also require a wider rear track in order to maintain the square tire size I'm currently pursuing. That's a whole different animal that what your after.

Not really a pro street layout, kind of a low level pro touring deal. Just trying to determine if i can get away with moving stuff in a little to get some dish on the rims. I won't be having square tire setup.

Thanks!