I'm new and need help

[Duster1446]

Hey folks I'm rather new to the Plymouth seen. I have mostly been a jeep guy. Rocks and mud and going slow got old so...
Any way I picked up a 72 duster from a good friend of mine. It was his drag car for a while and it pissed him off so much he just let it sit. So I got it and built it up and had it on the road in 2.5 months.
2000 era 360 magnum, mild cam other few goodies.

Any way my issue. It has the pro stock rear leafs in it. And that gives a good bit of rake. It was a slant 6 car. The hole front suspension was swapped out of a V8 car. Including the K.
I put new shocks in and everything feels tight.
So what it's doing. Going down the road it's like riding a hula dancer. It just wanders back and forth side to side. And god forbid you hit a crest of a hill at any speed. It pulls to the left and flips out like some crazy kid in math class.
Ball joints are good, wheel barings are good.
Any help would be greatly, greatly appreciated.

 

[Jim Lusk]

Check the alignment before anything else. You could also have worn out steering components, including the gear.

 

[memike]

If it was a drag car it could have slant 6 torsion bars in it, light and transfers weight to the rear end for drag racing. A good tech here can tell you what to look at.
Yes and a good alignment like Jim lusk said.

 

[godfatherofchry]

find a good front end shop and line the front end with you in the car.and it will be allright..Artie

 

[Duster1446]

Could the steering box be shot?. It was really tight. Perhaps it being over tightened messed with the gears inside.
I'll double check everything you all suggest. Any thought are great.

 

[crackedback]

Bias tires?

 

[Duster1446]

Nope. Even tryed 4 other brand new tires.

I'm starting to think bushings. I also have a vibe. And I went under and moved the DS around and it wiggles at the spline end on the trans.

Eventually I want to do the Hotchkis setup on it, so I kinda don't want to sink all kinds of money into stuff I'm going to take off soon. I just wanted to get it out and play for the summer before it goes under the knife again. Yet safe.

 

[adriver]

You may have more than one “issue” here. Sounds like people have got you on the right track.

Here’s something FYI. I believe I got it from the MOPAR Chassis manual by Larry Shepherd.
Mopar designed the leaf springs to have very little or no arch under load to improve handling. (on the street)
So what most people see as “flat” leaf springs really may not be a problem.
Seems like the only exception to that was the AAR and T/A to raise the rear a little for exhaust clearance.
I thought a Challenge I had was too flat in the rear.
I bought new MOPAR springs and it made no difference.
I learned the expensive way.
But more pertinent to your problem is that the stiffer a rear end is in relation to the front end the more over steer you get. (Twitchy).
And the stiffer the front is in relation to the rear the more under steer. (more stable)
I think I have that right.
Slant Six torsion bars ?
Your car may or many not have had them even if it was a slant car.
Just saying. It was Chrysler.
I put factory junk yard anti-sway (bar) front ends on my A bodies and they handle great.
I got some of those off of four door slant cars.
No rhyme or reason.

 

[Rob_Mopar]

Hi Guys,

I'm his buddy that sold him the Duster. I'm suspecting the alignment is off. The bugs are slowing getting sorted out.

The car was originally a '72 slant six. Another buddy of mine got it to replace his rusty '74 360 car. The '74 donated the entire front suspension, disk brakes, K, etc., including the torsion bars and factory sway bar.

Out back it's running a B-body 8 3/4 on 002/003 Super Stock rear springs. It now has (somewhat) skinny 205/70-15's up front on 5.5" wide steelies and 275/60-15's out back on 7" wide steelies. The car does have a serious rake to it.

When the suspension was swapped over (about 10 years ago) fresh bushings and ball joints went in. The bushings have some minor dry rot in them, but still have plenty of life left in them.

The car has a 15 gallon fuel cell in the trunk.

The hula dance has been reduced significantly after swapping in a fresh set of shocks and giving the fuel cell a full belly.

I don't have the current alignment numbers. I didn't have it on a rack in the time I owned it, but I'm suspecting the toe is off and the caster is probably less than ideal.

-Rob McCall

 

[dano]

The bushings have some minor dry rot in them

If they have any rot I would replace them, they are not working to there potential. Cheap insurance for your safety.

 

[Rob_Mopar]

After a little more sorting out I think he has it in good shape now. :thumbrig:

Three shocks were tired and one was completely shot. I gave him a good set of KYBs that came out of my '68 Barracuda when the adjustables went in. The "new" shocks tamed the Duster's hula dance.

He also had a different buddy do a quick check on the alignment and they readjusted the toe. That seems to have resolved the twitchyness he was experiencing.

He was out racking up some miles on it earlier this evening. If timing works out he might have it up at the Mopar Action show at Maple Grove this upcoming weekend. 8)

 

[cudaute]

Use heavier tie rods and sleeves I garauntee tighter steering 74 fury bolt up to abodies 100 bucks autozone