Lowering the back of my duster..ideas?

[74duster383]

I'd like to bring down the back of my duster.  leaf spring car.  Any ideas?  I have the JRS springs bought through JC whitney.  Drag raced last year one weekend, they seemed to work fine.  Mopar performance shocks through summit racing for an A-body.  The back end seems real stiff, seems to launch good but I would still like to get the rear of the car down some. 
Car is mini-tubed, springs moved under frame rails.

I don't know how safe lowering blocks between the rear and the springs would be. 

Another idea would be risky, but I could cut off the rear frame rail about 18" from the back end, fabricate it so the rear leaf spring hanger actually sits up in the trunk area thereby lowering the back end down.  If that don't work then it would be hard to put it all back.  But it would almost sit like a back halfed car but still have leaf springs.

Any Ideas or anyone try one of the above ideas?

[gt]

A few people have said that 2" lowering blocks would be the limit to put in between the springs and axle.
I would try that.

gt

[73swinger]

Did you move the spring under or into the frame rails? On my spring boxes there are 2 sets of mounting holes for setting the height

[7173Duster]

I used blocks made from bar stock the same width as the spring, radiused the edges so they don't cut into the spring, drilled holes completely through the blocks, removed the locator pin from the leaf springs, bought longer locating pins so I could bolt through the lowering block and the spring and let the pin hold them together.  In this way I don't have to worry about a small piece of cast metal breaking off and letting my rear end shift when the front wheels are off the ground. 

I'm prone to overthinking things and overkill though.

[blasphemous]

I used blocks made from bar stock the same width as the spring, radiused the edges so they don't cut into the spring, drilled holes completely through the blocks, removed the locator pin from the leaf springs, bought longer locating pins so I could bolt through the lowering block and the spring and let the pin hold them together.  In this way I don't have to worry about a small piece of cast metal breaking off and letting my rear end shift when the front wheels are off the ground. 

I'm prone to overthinking things and overkill though.

This is referred to an "add-a-leaf" in 4x4's.  Very secure way to add a small amount of lift, or drop in this case, of 1" to a leaf spring.

[74duster383]

Thanks for the responses.  I think I'm going to try the lowering block kit in the above post from summitt. 

Anyone have any advise on how high the front end is set using the torsion bars?  All I did was look at other cars either in person or in pictures and try to set the height of my front end to look the same.  How high does anyone else have their front set in relation to the rear.  Meaning, on a flat surface if I measure the ground to the bottom of the rocker panel right in front of the rear tires and then measure right behind the front tires, is it even, front lower, front higher etc.

Thanks

[bOb shingler]

try this for lowering your hotrod. remove the front spring hanger and weld some metal the same thickness as the hanger, fill in that angle with it and maybe even make it higher. then drill your new hole as high as you need it. for a few bucks more remove the rear shackels a replace them with a slider.

[Ciscodog]

That front hanger can be flipped upside down to gain you an inch or so.  FREE.

[bigtimeauto]

You can also pull a leave or 2 out. I took 2 out of my challenger SS pack and its sits fine.

[moparrr07]

sliders

[Ciscodog]

sliders

That won't lower the car.

[blasphemous]

sliders

That won't lower the car.

How not?  It seems that it'd remove all the height that the shackle adds.  (replacing a 4" shackle w/ a slider should net a 1" drop at least... right?)

[Womanator]

When I had the rearend narrowed on the 67 Dart Iknew I was going to use SS springs and I don't like the way the car sits with them on so I had the chassis guy weld new spring perch's on that were also spacer's and that gave it a good ride hieght.Not sitting highter on the passenger side.Also it doe's 1.55 60 ft time's with limited traction because of the tire's I gave the driver last year.The car ran a best of 11.18 without being able to launch hard out of the hole.

[74duster383]

If I take a leaf out of each spring, is there any best one to take out?   

[392dart]

i took mine to a sping shop and had them take some of the arch out

[Ryan (Strange246)]

i heard that sliders will put stress on your rear frame rails

No more than the stock shakles do...And yes sliders do get you about an inch lower..

Ryan

[Ciscodog]

sliders

That won't lower the car.

How not? It seems that it'd remove all the height that the shackle adds. (replacing a 4" shackle w/ a slider should net a 1" drop at least... right?)

The slider only has a set range.  If you move it farther toward the rear of the car it would lower the car, yes.  But then you'll have the problem of the rear being limited in how much it will travel away from the body.  If you put the slider in the correct spot, you won't lower the car.

[PureGTS]

  I've had as much as 3 1/2" lowering blocks on my RR, back when a slammed car was the thing. I still kinda like the "square" car slammed with big tire look. Real pain in the tucus to get tires on and off of being that low.  But I've found my brain since then and I now have just a 1" block to maintain the proper ride height. The BEST way to do it is to have the springs DE-arched. In the build for the "Green Brick" Mopar Action did, they took SS springs and had them de-arched 2" to lower the car and increase the rear ends spring rate to stiffin it. By de-arching it doesn' screw around with the driveline angle nearly as bad as installing blocks. Add blocks add wedges to correct too. Take this from the guy with 3 1/2" blocks on his shelf.  The last I checked my local spring shop wanted $70 each to de-arch ($140) SS springs 2". Someday I need to take them up on that.

[Womanator]

There's no way I would just put lowering blocks under my springs without welding them in.How would you get the pinion angel right.If you used wedges to correct you pinion angel you would just make your rearend that much more unstable.I saw a Roadrunner at the Woodburn Or strip twist the back axel right off the springs by bolting on the lowering blocks.As far as the pinion angle goe's you set it before you weld in the blocks.Dad always told me measure twice and cut once.(I'm 51 Dads thought has stuck with me)

[Josh]

Like Cisco said flip the front spring hanger. This works great.
It does not put any stress on the springs like lowering blocks.
By adding lowering blocks you basically put a longer lever from the housing to the spring increasing the spring wrap.  I ran my 74 with SS springs and flipped front brackets and it worked flawlessly.

[74duster383]

I understand the concept of flipping the front spring hangers but in my case I have move the springs with the relocation kit so I don't use the front hangers anymore.  To accomplish the same thing I could move my mounting point higher in the box thereby lowering the front a little. 

Thanks for all the replys.   

[A13Dart]

Like Cisco said flip the front spring hanger. This works great.
 It does not put any stress on the springs like lowering blocks.
 By adding lowering blocks you basically put a longer lever from the housing to the spring increasing the spring wrap.  I ran my 74 with SS springs and flipped front brackets and it worked flawlessly.

Bet you had to drill the holes way oversize to do this, cause the bolt pattern isn't symmetrical.