All About Suspension Upgrades

RebelautoengrLLC

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Hello! I tried searching this forum for threads regarding my curiosity without success. I would love to know if anyone out there has any opinions (I admit that's a loaded question) on suspension upgrades. For the record, I would like my Coronet to handle well. It's not going to be a tack car. I just want to drive it around the metro Detroit area and enjoy doing it. I'm going from a /6 to 440, so I have V8 torsion bars. I'm looking to put a front sway bar on it and a rear (if anyone has experience or has done so, please share). I would also like to ditch the rear leafs and put a coil over set up on.

Not looking to spend a lot of useless fiat on it, but let me know your thoughts or share advice. Thanks!
 

multimopes

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To each his own & according to each budget. Way back in the day, I had a 70 Challenger RT. It had the front sway bar but not the rear so I added it. It also had cut out & re-finished fender wells at all 4 corners. Of course, the fattest bias ply tires were used as well. I cranked the front torsion bars up all the way, installed front 90/10 drag shocks & installed Gabriel Hi-Jackers in the rear with shock extenders inflated to the maximum 140 psi. with an added helper leaf spring. Well, I can say it wasn't a smooth ride for sure, but that car handled like a dream; never leaned at all. I could out handle nearly anything else I came across, except on bumpy roads, which ruined my kidneys, lol. With the factory (over) powered steering, I could slide like a drift car and spin it around with 2 fingers on the wheel while cracking the throttle on that ol' 383. I know that's not the answer you are looking for but I love to tell it and I sure do miss it today! By the way, the police loved me as the car was sublime green and stuck out like a sore thumb!
:lol:
 

RebelautoengrLLC

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Has anyone here heard of / seen / attempted to take a Jeep Dana 44 and modify it to fit in a B body? A Dana 60 B original is going to be out of my budget. I believe that would get me something better than a Chrysler 8 3/4 and I could utilize the pads for coils. I know it would most likely require modification, but.... I would be able to know out two birds with one stone.
 

Superbeemike

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A Dana 44 from a JK just might work with some fab work. They come with disc brakes and have a E brake built in too. There is plenty of support to upgrade axle shafts, gear sets, and carriers. Swapping to a 4 link will prove difficult, but not impossible. I’d challenge the strength of the Dana vs the 8 3/4. I’ve seen 8 3/4’s take a beating.
 

1967coronet

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Dana 44 or 8.75
I would keep the 8.75 jmho.
 

DodgeDos

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I added a Hotchkis front sway bar on my 66 coronet. I have a wide block so just a little lighter than the 440. It made such a difference that I kick myself for not doing it sooner.
 

1967coronet

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The 8.75 is built better axle wise and I pretty sure has larger pinion bearing set.
Tons of aftermarket support. Easy to swap center chunk.
They hold up great , the max wedge cars of the 60s put a pretty fair test on them :D
Nothing wrong with the 44 but if I had both I know what one I would choose.
 

Nate S

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Learn about, and pay attention to geometry. As you mess with ride height in the front and axle arch in the rear you also mess with the intended body lean steering. Many simply go for ultra stiff springs, that can work but you also can get equivalent handling with lighter springs if you keep your eye on the geometry and front-rear spring rate balance.
 

rmchrgr

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Keep the 8 3/4, you’d be creating a lot of work for zero benefit and added complexity. It's plenty stout. As mentioned already, factory Hemi cars had them. Dealers don't want people coming back to fix stuff under warranty so if there was any question about the strength of an 8 3/4" Chrysler would have put Dana 60's under anything that had a big block in it.

Personally, I've never heard of anyone doing this particular swap. First, if it's from a 4x4 it’s usually in the front so the driveshaft offset would be in the wrong spot. As with any custom rear end you’d most likely be cutting the original tubes off to make it work under something it was never designed to be used in. At that point you’d be in for housing ends, custom axles and brakes with the proper axle bolt pattern, u joints, etc. Even a Ford 9" would be easier and stronger than a Dana 44.

IMO, your idea to use rear coil overs would likely be a fairly big hassle as well. Leaf springs can be custom made to any spec you want, no need to reinvent the wheel. Why do you think you want/need them? One major thing to consider is how you would mount them. Besides the flats on the axle tube, a true coil spring needs some sort of upper cup/retainer to locate them between the axle and chassis. That's definitely not happening without major chassis surgery/fabrication that needs some solid engineering behind it. Probably would need a trailing arm/panhard bar as well like a GM car. Kinda need to have some pretty good ideas and skills to tackle that job. Unless you're just thinking about those regular shocks with coils wrapped around them? Those have never made much any sense to me.

Honestly, unless you are drag racing a heavy car with a 4 speed that launches at 7,000 rpm, a properly built and maintained 8 3/4" rear will outlast you for regular street duty and most “spirited” driving. if you're that worried about it, back brace it and never think about it again.

Regarding suspension ideas, first thing I would suggest is to stiffen the body with frame connectors. If you do anything, do that and do it before anything else. It will improve overall rigidity and helps to reduce that famous Chrysler body roll.

To provide a real-world example, my ‘68 Coronet has some decent bolt on suspension upgrades; besides fully welded frame connectors we got 1.0” torsion bars, tubular upper control arms (that provide more caster than stock parts), 1” (bolt-on) sway bar, Borgeson quicker ratio steering box (more of a modern car feel than the original numb Mopar P.S. box), new heavy duty leaf springs, spring hangers and shackles. This is all riding on garden variety BFG radials and nuthin' fancy disc brakes.

Just this week I ordered a set of QA1 single adjustable shocks and am waiting on delivery.
Good shocks round out any suspension package by controlling body jounce and rebound inertia. Based on reviews people mostly have good things to say about these things. They ain't cheap so hopefully they live up to the hype and make some sort of noticeable difference. Honestly, just about anything would be an improvement over the current Mopar blue pogo sticks in the rear and KYBs in front.

It’s a basic package but it handles predictably and tracks well. It’s not your look-at me fender flared, ultra low, rubber band tire, Pro Touring/G Machine/road race/autocross bling mobile, just a fun, mostly stock style cruiser which gets driven often in lots of different situations.

And let’s face it, this wasn’t a dirt cheap deal by any means but its nowhere near the top of the suspension mod food chain and should be within reach for most people that mess with these cars.

Lots of options out there to make your junk handle even in a mild sense.
 

Commando66

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Here are the suspension upgrades that I did to my 67 Belvedere a month after I bought it.

1" torsion bars from Firm Feel
HD rear springs from
Polygraphite spring eye and shackle bushings from PST
Fox/Hotchkis shocks from Hotchkis
Front sway bar 1 3/8" hollow from Hellwig
New 20:1 manual steering box from Firm Feel
New tie rods, ball joints, pitman arm, idler arm from ProForged
New front disc conversion w/manual master cylinder.
8 3/4" 3.23 Sure Grip from wrecking yard

Like you said, you're not familiar with the 8 3/4". It's a tried and true heavy duty axle that can take lots of abuse.
 

joe smith

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I installed a Firm Feel rear sway bar in my 67 RT right after its resto.. It made an amazing difference in how the car cornered...
DSCF0111.JPG

I had a different brand to install that was less expensive than the firm feel.. I gave it away... The Firm Feel unit is the one to use
 

RebelautoengrLLC

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Keep the 8 3/4, you’d be creating a lot of work for zero benefit and added complexity. It's plenty stout. As mentioned already, factory Hemi cars had them. Dealers don't want people coming back to fix stuff under warranty so if there was any question about the strength of an 8 3/4" Chrysler would have put Dana 60's under anything that had a big block in it.

Personally, I've never heard of anyone doing this particular swap. First, if it's from a 4x4 it’s usually in the front so the driveshaft offset would be in the wrong spot. As with any custom rear end you’d most likely be cutting the original tubes off to make it work under something it was never designed to be used in. At that point you’d be in for housing ends, custom axles and brakes with the proper axle bolt pattern, u joints, etc. Even a Ford 9" would be easier and stronger than a Dana 44.

IMO, your idea to use rear coil overs would likely be a fairly big hassle as well. Leaf springs can be custom made to any spec you want, no need to reinvent the wheel. Why do you think you want/need them? One major thing to consider is how you would mount them. Besides the flats on the axle tube, a true coil spring needs some sort of upper cup/retainer to locate them between the axle and chassis. That's definitely not happening without major chassis surgery/fabrication that needs some solid engineering behind it. Probably would need a trailing arm/panhard bar as well like a GM car. Kinda need to have some pretty good ideas and skills to tackle that job. Unless you're just thinking about those regular shocks with coils wrapped around them? Those have never made much any sense to me.

Honestly, unless you are drag racing a heavy car with a 4 speed that launches at 7,000 rpm, a properly built and maintained 8 3/4" rear will outlast you for regular street duty and most “spirited” driving. if you're that worried about it, back brace it and never think about it again.

Regarding suspension ideas, first thing I would suggest is to stiffen the body with frame connectors. If you do anything, do that and do it before anything else. It will improve overall rigidity and helps to reduce that famous Chrysler body roll.

To provide a real-world example, my ‘68 Coronet has some decent bolt on suspension upgrades; besides fully welded frame connectors we got 1.0” torsion bars, tubular upper control arms (that provide more caster than stock parts), 1” (bolt-on) sway bar, Borgeson quicker ratio steering box (more of a modern car feel than the original numb Mopar P.S. box), new heavy duty leaf springs, spring hangers and shackles. This is all riding on garden variety BFG radials and nuthin' fancy disc brakes.

Just this week I ordered a set of QA1 single adjustable shocks and am waiting on delivery.
Good shocks round out any suspension package by controlling body jounce and rebound inertia. Based on reviews people mostly have good things to say about these things. They ain't cheap so hopefully they live up to the hype and make some sort of noticeable difference. Honestly, just about anything would be an improvement over the current Mopar blue pogo sticks in the rear and KYBs in front.

It’s a basic package but it handles predictably and tracks well. It’s not your look-at me fender flared, ultra low, rubber band tire, Pro Touring/G Machine/road race/autocross bling mobile, just a fun, mostly stock style cruiser which gets driven often in lots of different situations.

And let’s face it, this wasn’t a dirt cheap deal by any means but its nowhere near the top of the suspension mod food chain and should be within reach for most people that mess with these cars.

Lots of options out there to make your junk handle even in a mild sense.


Thank you very much for sharing this! There's a lot to digest. I'm definitely not looking to have some obnoxious low rider, wide bodied car that you see on tv. I love the classic look, but I just want some modern handling to it. I wasn't a fan of the "boat" feel the car had the day I drove it home. I had a Scion FR-S, and I know it's asking a lot, but I loved how that car handled. It wasn't fast but was so much fun to drive around.

One thing that I'm curious about is in the section you talk about your '68 upgrades and you mention the tubular control arms that are able to provide more caster than stock? What degree did you set them to? For some background on my set up, I bought some of the repro ~'73 B disc brake spindles.

Another reason why I ask about a JK dana 44 swap is (I'm hoping that they are similar widths) it already has discs on the rear. I cannot overstate how much I dislike working on drum brakes. I can do it, but I'm sure you know, there's always some serious hassle to deal with when servicing them (hopefully that doesn't give up my age as I'm pretty accustomed to discs). I also have a eaton trutrac for a dana 44 sitting in my shop that would be great to use up. I really appreciate everyone chiming in on the 8 3/4. I'm going to study them some more and see if I can find a line on one.
 

rmchrgr

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Thank you very much for sharing this! There's a lot to digest. I'm definitely not looking to have some obnoxious low rider, wide bodied car that you see on tv. I love the classic look, but I just want some modern handling to it. I wasn't a fan of the "boat" feel the car had the day I drove it home. I had a Scion FR-S, and I know it's asking a lot, but I loved how that car handled. It wasn't fast but was so much fun to drive around.

My car handles pretty well, no floating, diving, wander or what have you. I drove a Mazdaspeed3 for 130K miles. The Coronet does not handle like that thing but I wouldn't expect it to, just a totally different animal. The Dodge has a significantly higher center of gravity and a much longer wheelbase, huge front and rear overhangs, basic 15" radial tires compared to 18" performance tires, parallelogram steering as opposed to an electric rack, bolstered buckets as opposed to flat '60s buckets and on and on.

Regardless, the Dodge drives well enough that you don't notice any ill handling effects or ever get a sense there is a lack of maneuverability. I live in a wooded area with lots of narrow, twisty roads and I've never had an issue pushing the car hard through the turns. Having a stick shift helps tremendously in that regard but it still does the job well.

One thing that I'm curious about is in the section you talk about your '68 upgrades and you mention the tubular control arms that are able to provide more caster than stock? What degree did you set them to? For some background on my set up, I bought some of the repro ~'73 B disc brake spindles.

The control arms are designed to provide 4 degrees more caster than stock control arms. The place that aligned my car could not get that much but if I remember I think they were able to get maybe 2 1/2 degrees more than the stock spec. but honestly it's great as-is. It was a regular tire place so take that for what it's worth.

Many people go with the '73-up disc conversion, they work well and are a relatively cheap upgrade. I've done it on two different cars without issue. I don't like them on A bodies because they push the wheels out too far and make the car look goofy but that has nothing to do with how they perform. They're also heavy but on a street car that probably doesn't matter too much.

Another reason why I ask about a JK dana 44 swap is (I'm hoping that they are similar widths) it already has discs on the rear. I cannot overstate how much I dislike working on drum brakes. I can do it, but I'm sure you know, there's always some serious hassle to deal with when servicing them (hopefully that doesn't give up my age as I'm pretty accustomed to discs). I also have a eaton trutrac for a dana 44 sitting in my shop that would be great to use up. I really appreciate everyone chiming in on the 8 3/4. I'm going to study them some more and see if I can find a line on one.

Nothing really to study, the 8 3/4 is a tried and true diff and durable as they come. Chrysler put them behind just about anything with a V8 during the muscle years. From A bodies to C bodies, in trucks, vans, etc. I've had them in all my cars, never had an issue with any of them. Again, as long as you're not trying to make it live behind a stick shift in a heavy drag car it will take whatever you can throw at it.

Honestly, they are much easier to deal with once in the car than a Dana because of the Hotchkis style (drop out) center section. You can change centers out pretty quickly, don't need to take a rear cover off, don't need a case spreader....just get the 44 out of your head.
Maybe sell the Trutrac to a rock crawler and use the coin to get some good 8 3/4 parts from Cass. He carries rear disc conversions for the 8 3/4 too but I don't believe it's totally necessary endeavor - it mostly just adds cost/complexity. Rear drums are great as long as they are setup correctly. Get some 7/8" wheel cylinders and you should be good to go.
 

Kern Dog

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It is common for people to drive a worn out classic car after spending years in modern cars and think that all the old style suspension is obsolete and needs to go.
If any of these people would just drive a properly functioning classic car, their perspective would likely be much different.
When the springs are in good condition and the bushings are not worn out, the classic cars still compare quite well to today's cars. The suspensions were designed around the tire science of the day. Since the 60s and 70s, tire science has improved greatly. The best street tires of today would be considered far out, exotic race type tires in 1970.
A 62-72 B body can be made to ride and handle quite well if the money is spent in the right places. Coil over suspensions whether it be in the front or rear is an unnecessary expense that may also be a step backward in durability. Drag race cars will benefit due to the reduced weight and the ability to tailor the spring rates for track conditions. For the guy that will cruise the car 1000 miles a year with a few burnouts and power slides peppered in, the stock stuff will be just fine.
 

RebelautoengrLLC

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This is all great information! I appreciate the input as you're making me rethink my plans so I don't unnecessarily spend money on useless endeavors.
 

Mike67

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Listen to what you are asking, as you can answer it already. This is going to be a street car not a track car. The 8.75 will serve you well.
Disc brake conversions ( used) come up for sale at regular intervals. Monitor this sites classifieds, FABO. Racing Junk and there are a lot of classified Mopar groups on FB.
My 67 has a Dana 60 out of a truck and is more than Il ever need. Personally I would have gone with the 8.75 or a 9" but thats what came with it as it was a drag car.
Ive put Wilwood disc on all 4 corners, have a QA1 front K member, tubular upers and lowers, PST 1.08 torsion bars, Qa1 srut rods with solid bushings and QA1 dual adjustable shocks on all 4, Borgenson power box and hydroboost.
I had plans of dual purpose street car, plans changed over time while assembling. I bought all of my parts second hand, unused from others cancelled projects for pennies on the dollar. The only thing brand new was the K member.
The suspension has just about every aftermarket upgrade outside of a rack.
Now take that all with a grain of salt as Im yet to put more than 50' on it moving in and out of the shop.
My best advice is: if money is a concern dont over think, over engineer what works fairly well as is. Buy some quality shocks, make sure all of your bushings, ends are all in good shape, even tires can make a big difference in the ride quality.
 

RebelautoengrLLC

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Yes... you guys have talked me off the ledge. I have the front suspension pulled and the bushings were all blown out. Granted, I never got the drive the car more than 50 miles before I started tearing it apart.... and let it sit for years. I've never been more determined to fix it and get it running again until now. I've made a list so I can stick to it and not overthink or over engineer as was previously stated.
 

Mike67

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Yes... you guys have talked me off the ledge. I have the front suspension pulled and the bushings were all blown out. Granted, I never got the drive the car more than 50 miles before I started tearing it apart.... and let it sit for years. I've never been more determined to fix it and get it running again until now. I've made a list so I can stick to it and not overthink or over engineer as was previously stated.
Post.some pics, we.love to.see what people.are working on!
 
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