What the best torsion bar and leaf spring combo?

I have a 73 dart that was a slant six car that I used a V8 K member to install a 340 with a 4 speed. The rear end is a Dana 60 out of a B body and I want to know what size of torsion bars should I use and springs to get the best handling. Its has stock slant six bars now and stock V8 springs in the back and it handles like crap.

depends what you're trying to do (and I have the same car and drivetrain except fopr the rear)

I used 1" torsion bars and Super STock leaf springs with Competition Engineering Drag Shocks all around. The shocks are set on medium. The car launches great and take corners pretty well, but I have 225-70R14 tires. Lower profile tires would go a long way for me lol.

Thanks ya I'm just wanting it to handle good on the street and ride decent.

I only have ~150 miles on my car, so it's not even broken in. It's definitely not a soft ride by any means lol. But there's no body lean and it drives straight.
I also have an addco front sway bar and a Hellwig adjustable rear sway bar. Those definitely help a lot.

Add a sway bar.

73340sport said:

Thanks ya I'm just wanting it to handle good on the street and ride decent.

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well, its both parts and tuning as with anything in street rodding.
There were a variety of leafs available even amongst the v-8 cars. If the leafs are really well used, like 80k miles, lots of cargo or people or drag race launches on slicks, they could simply be worn out. You local spring shop can sell you new. However I will say that not all replacement springs are equal in quality. Measure the thickness of the leaves as well as the number of leaves. Since you are running a strong engine and a heavy axle, a thick main leaf will help it last longer.

Torsion bars. For street use, use one of the largest the factory offered, or anything up to 1.03 in the aftermarket. Yes there is a big range in spring rates from .89" diameter to 1.03" but based on your question you'll probably be happy with almost anything in that spread. If you're running stick tires then lean higher, if you don't like stiff rides or are using a typical street tire (eg BFG Radial TA) then stay in the .89-.99 range.

A front Sway Bar will make the most noticible difference. Use polyurethane bushings for the sway bar and end links for the best response.

On the tuning side, set your ride hieght a little on the low side (say 1.5" using chrysler method of measuring front ride ht) and align for a little bit of negative camber, 1-3 degrees of positive caster, and just a little bit of toe in so its close to zero when moving.

~1" torsion bars, XHD springs in the back, front and rear sway bars, Bilstein shocks. Also add subframe connectors if you don't already have them. Alignment should be around -.5 degrees camber, +3 caster, 1/16 to 1/8" toe in. Factory alignment specs are for bias ply's and are horrific for anything else. Modern tires will also make a huge difference, and I don't mean BFG T/A's.

72bluNblu said:

~1" torsion bars, XHD springs in the back, front and rear sway bars, Bilstein shocks. Also add subframe connectors if you don't already have them. Alignment should be around -.5 degrees camber, +3 caster, 1/16 to 1/8" toe in. Factory alignment specs are for bias ply's and are horrific for anything else. Modern tires will also make a huge difference, and I don't mean BFG T/A's.

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X2
This is how my setup will be when Im done. So far ive got XHD springs, hellwig front 1 1/8" sway bar and sub frame connectors with the same alignment specs.

The frame connectors and big sway bars will be the biggest improvements to handling.
If the car has to much bounce in the front, then a thicker T-bar is needed.
If your rear wheels hop on acceleration, you need springs.

if ya really wanna go nuts, use the Hotchkis TVS kit.

rumblefish360 said:

The frame connectors and big sway bars will be the biggest improvements to handling.
If the car has to much bounce in the front, then a thicker T-bar is needed.
If your rear wheels hop on acceleration, you need springs.

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Sorry, but they ALL need torsion bars. None of the stock bars are even close to the right spring rate for half decent handling. Maybe the .92" bars, but only for a small block car. You can have a nice cruiser with smaller bars than that, but it won't REALLY handle.

Tires are probably the single biggest improvement. Sway bars and subframe connectors are important, but you won't use them to half their potential without a set of decent tires. (NOT BFG T/A's!).

mopardude318 said:

if ya really wanna go nuts, use the Hotchkis TVS kit.

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That's a really well matched kit. And honestly, you can do it cheaper if you really pay attention, but if you replicate that kit piecemeal you're going to spend a ton of money. Maybe not as much as the kit costs, but close enough to make the kit worthwhile.

Big savings over the TVS kit is not replacing some of the stuff included, like the tubular UCA's and tie rods. Stock UCA's with offset bushings, and even stock tie rods are fine for a car that doesn't get track time. You can also buy solid tie rod adjusters for a lot less, and that takes the flex out of them. Then you're down to torsion bars, rear springs, sway bars and adjustable strut rods, all of which I would keep. But you can get 1" to 1.03" bars for around $200, XHD's for $230, sway bars from around 350 up to 600 (addco up to hotchkis), and adjustable strut rods from Dillinger for $155.

Even with the Hotchkis sway bars you're at ~$1200. Then add a set of subframe connectors (which aren't in the TVS kit, I don't know why), LCA boxing plates and a set of modern tires on 17x8's and you've got one sweet handling ride.

The other thing about the TVS kit is the rear springs. They're awesome handing springs, but they sit the car a lot lower than I think most people want. Yes, the lower car will handle better, but even an XHD sprung car will handle pretty darn well with the rest of those components. Same with the hollow Hotchkis sway bars. Yup, they're better than a set of solid Addco's, but unless you REALLY push the car you probably won't notice.

72BnB I get the drift from your post like you did my read mine or understand the T-bars are for up and down motion. Shocks handle the second portion of that issue. A well handling ANYTHING from those years just doesnt happen.

If you don't like the amount of motion it travels up and down and your shocks are good, the it's the T-bar your looking at. Read! Tasters choice and NOT YOUR OPINION!

rumblefish360 said:

72BnB I get the drift from your post like you did my read mine or understand the T-bars are for up and down motion. Shocks handle the second portion of that issue. A well handling ANYTHING from those years just doesnt happen.

If you don't like the amount of motion it travels up and down and your shocks are good, the it's the T-bar your looking at. Read! Tasters choice and NOT YOUR OPINION!

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I did read your post. And I do understand that up down motion is torsion bars and shocks. And I even forgot to mention shocks, which is silly because they're one of the more important aspects of a well balanced car, especially one with larger torsion bars.

But I disagree that a well handling anything from those years doesn't happen. The Hotchkis TVS cars are pulling more than 1.0 latergal G's on the skid pan, and that is better than many new cars.

LOL, OK, is see the issue. I was thinking stock anything!
BAHA ha ha ha ha.....

I'm with you on the aftermarket setting us up nicely. Though somewhat a bit pricey for my pockets these days. (Dang collage is expensive! 1 down, 2 to go!)

rumblefish360 said:

LOL, OK, is see the issue. I was thinking stock anything!
BAHA ha ha ha ha.....

I'm with you on the aftermarket setting us up nicely. Though somewhat a bit pricey for my pockets these days. (Dang collage is expensive! 1 down, 2 to go!)

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Sorry 'bout that! :mrgreen:

Yeah the aftermarket has come around quite a bit in the last few years for setting up these cars for decent (even great!) handling. But it's definitely not cheap. I even forgot that the TVS system doesn't include torsion bars! Lots of nice goodies, but I think they could come up with a better package for most cars- ie, lose the tubular UCA's and fancy heim joint tie rods and replace them with torsion bars and subframe connectors, or maybe even add in the shocks. Much more practical. But, if you're going the full monte, the TVS system is still a good choice. You just need a couple more things for the entire set up.

If you add good shocks into the list I put up, you're in the $1,700 to $1,800 dollar range (Fox or bilsteins). And that still doesn't include rims and tires, which for decent 17's or 18's will run in the couple thousand dollar range.