Finalized upgrade part list

[Spartan040]

I'm planning out a 1970 Challenger build with a 440/512 EFI stroker, and a GV 727 auto, and I think I've finalized my list of suspension upgrade parts.
This is my current (possible) list of upgrade parts:

US Car Tool Chassis Stiffening Kit
Borgeson P/S Conversion Box 1-1/8" Sector Shaft
Firm Feel E-Body 1.18 Dia Torsion Bars w/ dust boots and adjustors
Hotchkis Geometry Corrected Tubular Upper A-arms w/ protective boot kit
Hotchkis Sport Sway Bar set
Hotchkis Geometry Corrected Sport Leaf Springs
Hotchkis Tuned 1.5 Adjustable shocks
Hotchkis Adjustable Steering Rod Kit
Hotchkis Adjustable Strut Rods
Firm Feel Fast Ratio Steering Arms
Hotchkis Pivot Shaft & Bushing Kit
Doctor Diff. Strange S60 Rear End w/ 35 spline axles, TrueTrac Carrier, 3.23 gears, 1350 large aftermarket yoke
Baer Front and Rear Pro + Brake Kit

It's either all this, or an RMS AlterKtion front end and Street Lynx rear, along with the chassis stiffening kit. My goal is to make this handle as close to a modern car as possible, like a 2015 Challenger (they recently did many suspension upgrades), so that it can keep up with (or at least come as close as possible to) modern cars on a track or the street. Money isn't my main concern here, I just want to know what system will give me the best performance. What has the best turning radius, the best stability, the least body roll, and which can handle at speed the best.

Also, is there anything here I should add or discard? Anything that might work better?

[1 Wild R/T]

Yeah, get rid of the big block...   Either a big small block or a gen 3 Hemi..... Heck do a Hellcat engine/trans....  Lighter, plenty of HP & torque...

[Spartan040]

Yeah, get rid of the big block...   Either a big small block or a gen 3 Hemi..... Heck do a Hellcat engine/trans....  Lighter, plenty of HP & torque...

Don't get me wrong, I'd absolutely love a gen 3 Hemi, that'd be badass, problem is I've heard the swap is a very long, involved, and difficult (for someone like me with limited experience) process. There's the fitting issues, and getting the electrical systems to mesh. Why get rid of the big block though? If its for weight savings, I could always use an aftermarket aluminum block for the 440, along with aluminum heads and all the other weight saving things. It's also one of the most reliable and bulletproof engines Chrysler every built and has a ton of performance potential. Not to mention, it's cheaper to do a 440 build. And, I'd love to have that feeling of pride when I say I built that motor from the block up, and that I transformed an old engine into something new and better.

What clear advantages does the gen 3 Hemi have over a light(er) weight performance built 440/512 stroker with electronic fuel injection, that would make it worth the extra time and money spent doing a gen 3 swap? If fuel economy is one reason, ask Chryco Psycho, he built a couple 440/512 motors that could get around 20 mpg highway. By the way, I don't mean to come across as challenging or angry, I appreciate the input. I just need to know if the hassle of a swap is really, really worth it.

[BergmanAutoCraft]

Having run open track events with my Dart and worked with others to do so, I'd be carefull using an automatic. Typically, they overheat pretty fast. I also prefer to use an upper control arm that doesn't need to be removed to be aligned. For drag racing I like the fact that the anti dive has be engineered out of the H arms. They seem to allow the rear to squat more. One thing you didn't mention is tires and wheels which are probably the most important. I use a hybrid street road race tire - falken 615K with success. Commenting on the end of your post, rack systems are usually good too, but turning radius usually suffers. I've seen this with all kinds of systems.

[1 Wild R/T]

Peter, If your interested in commenting on it, what are your feelings on Alterkations flawed Ackerman angle? I've never driven an XV equipped E body but I've now driven two Alterkation equipped Challengers & on both the Ackerman angle was so far off that even on moderate turns you feel the car bind due the the dissimilar turning radius, on a parking situation it's so bad you feel the car bind till the tire actually slips & "steps over" correcting its position...

[ToxicWolf]

Check out my restoration thread (link below). I'm using a lot of the parts you have listed. Very happy with the Hotchkis and Car Tools stuff. 

[brads70]

That might be too much torsion bar for the rate those Hotchkis rear springs are at? I have 225 rears with a 1.120 torsion bar and it's slightly loose when pushed to the limit. ( which I prefer instead of a push!) Also I don't think the Dana can be had with a 3:23 rear gear?  I'd suggest matching the rear gear to the power band of the cam shaft. I too have a Dana with 3:55 with an OD transmission and wish I had went with 3:73 as the engine is not "happy" at 65 MPH , it likes 80 MPH better but law enforcement doesn't so much.    Like Peter suggested tires make a big difference, I too am using the Falken 615K tires in 18"

[BergmanAutoCraft]

"Peter, If your interested in commenting on it, what are your feelings on Alterkations flawed Ackerman angle? I've never driven an XV equipped E body but I've now driven two Alterkation equipped Challengers & on both the Ackerman angle was so far off that even on moderate turns you feel the car bind due the the dissimilar turning radius, on a parking situation it's so bad you feel the car bind till the tire actually slips & "steps over" correcting its position"

Randy - I don't want this to turn into a bashing session. I prefer to phrase my comments in a way that make people understand what the parts they buy actually do, then have them decide if they are "right" for their builds. I own and operate a shop and make/sell the Borgeson steering boxe kits, delrin lower arm bushings and SPC upper arms with my ends on them. For that reason I need to be even more careful. Since I have a ton of experience with this market, as well as my own car, I feel qualified to comment.

In general, when I look at aftermarket suspension systems I look at a few things:

1. Length of shocks. Our mopars use a 5" shock. Normally, the longer the shock the better the ride.
2. Bumpsteer arrangement. Most aftermarket systems use something to take up the space between the steering arm and the tie rod end. This is the result of a packaging problem. The fix seems like a bandaid to me.
3. Turning radius. Except for factory cars, racks usually result in reduced turning radius.
4. Size of the wheel bearings. In a open track setting, the mopar bearings aren't large enough to counteract the lateral movement of the hub. This results in pad knock back. I run Timken bearings with good pre load and mopar long fiber grease and 14" SRT rotors and 4 piston Viper calipers. This would not be as noticeable with a smaller rotor and a floating caliper.

These 4 things alone prevented me from going this route on my Dart.

[Mpdlawdog]

 

[drewcrane]

"Peter, If your interested in commenting on it, what are your feelings on Alterkations flawed Ackerman angle? I've never driven an XV equipped E body but I've now driven two Alterkation equipped Challengers & on both the Ackerman angle was so far off that even on moderate turns you feel the car bind due the the dissimilar turning radius, on a parking situation it's so bad you feel the car bind till the tire actually slips & "steps over" correcting its position"

Randy - I don't want this to turn into a bashing session. I prefer to phrase my comments in a way that make people understand what the parts they buy actually do, then have them decide if they are "right" for their builds. I own and operate a shop and make/sell the Borgeson steering boxe kits, delrin lower arm bushings and SPC upper arms with my ends on them. For that reason I need to be even more careful. Since I have a ton of experience with this market, as well as my own car, I feel qualified to comment.

In general, when I look at aftermarket suspension systems I look at a few things:

1. Length of shocks. Our mopars use a 5" shock. Normally, the longer the shock the better the ride.
2. Bumpsteer arrangement. Most aftermarket systems use something to take up the space between the steering arm and the tie rod end. This is the result of a packaging problem. The fix seems like a bandaid to me.
3. Turning radius. Except for factory cars, racks usually result in reduced turning radius.
4. Size of the wheel bearings. In a open track setting, the mopar bearings aren't large enough to counteract the lateral movement of the hub. This results in pad knock back. I run Timken bearings with good pre load and mopar long fiber grease and 14" SRT rotors and 4 piston Viper calipers. This would not be as noticeable with a smaller rotor and a floating caliper.

These 4 things alone prevented me from going this route on my Dart.

Great info

[Spartan040]

So far I'm liking my idea of the pieced together Hotchkis stuff. Are there any real advantages to the AlterKtion and Street Lynx other than reduced weight? Does it perform just as well or better? Will I have a tighter or wider turning radius?

[Chryco Psycho]

"Peter, If your interested in commenting on it, what are your feelings on Alterkations flawed Ackerman angle? I've never driven an XV equipped E body but I've now driven two Alterkation equipped Challengers & on both the Ackerman angle was so far off that even on moderate turns you feel the car bind due the the dissimilar turning radius, on a parking situation it's so bad you feel the car bind till the tire actually slips & "steps over" correcting its position"

Randy - I don't want this to turn into a bashing session. I prefer to phrase my comments in a way that make people understand what the parts they buy actually do, then have them decide if they are "right" for their builds. I own and operate a shop and make/sell the Borgeson steering boxe kits, delrin lower arm bushings and SPC upper arms with my ends on them. For that reason I need to be even more careful. Since I have a ton of experience with this market, as well as my own car, I feel qualified to comment.

In general, when I look at aftermarket suspension systems I look at a few things:

1. Length of shocks. Our mopars use a 5" shock. Normally, the longer the shock the better the ride.
2. Bumpsteer arrangement. Most aftermarket systems use something to take up the space between the steering arm and the tie rod end. This is the result of a packaging problem. The fix seems like a bandaid to me.
3. Turning radius. Except for factory cars, racks usually result in reduced turning radius.
4. Size of the wheel bearings. In a open track setting, the mopar bearings aren't large enough to counteract the lateral movement of the hub. This results in pad knock back. I run Timken bearings with good pre load and mopar long fiber grease and 14" SRT rotors and 4 piston Viper calipers. This would not be as noticeable with a smaller rotor and a floating caliper.

These 4 things alone prevented me from going this route on my Dart.

 Thanks for the info , this is exactly what I had heard about RMS although I have never driven one .
Front steering & Mopars has yet to be truely sorted out IMO

[BergmanAutoCraft]

I never said anything about RMS.

[HP2]

RMS, Reilly Motor Sports, Bill Reilly, Alterkation...all one in the same.

For drag racing I like the fact that the anti dive has be engineered out of the H arms. They seem to allow the rear to squat more.

This is a positive for a GM that uses a coil spring suspension, or for many aftermarket coil over systems, but is actually not the preferred method of launching a mopar with asymmetrical springs. The biased control ratio of a mopar leaf generates lift. This body separation on launch is preferred over a squatting launch. This lift is what motivated John Calvert to create  the Cal-track system that allows leaf spring Fords and GMs to generate spring action more along the lines of what a mopar has out of the factory.

[Spartan040]

Just to get this straight, are the Hotchkis components along with what I listed about equal to the coil-over suspension kits in terms of performance? My whole goal here is a pro-touring / resto mod type of car that's able to do well on the street, strip, and autocross track. Are there any real advantages to the coil-over systems besides weight loss and a custom look? And just out of curiosity, what might happen if I took out the rear suspension components and replaced them with a Street Lynx kit?