Charger build discussion

[Brutalowner]

Im finally getting ready to update my Charger to make it perform like a modern LX chassis car, with the primary focus on the handling. The plan seems pretty simple and straightforward, but id like to hear input on the parts selection, mainly bar diameters.
Here is what Im working with-
1969 XP 318/904/ power drums, a/c p/s console car.
Completely stock. Owned since 1982.

What I have for the project.
Blueprint 408 that dyno'd 477hp
a built 727 with appropriate stall
aluminum 1350 driveshaft
8.75 rear with sure grip and 3.23/3.55/4.10- 3.23 being the primary use gear
Mopar XHD springs
15 x 8 Magnums
10.7 rear discs
Disco-tech style 11.7" front discs
tuned up and gusseted LCAs
Qa1 strut bars
Firm Feel UCAs
Borgeson box
1-3/8" anti sway bar
.940" R/T torsion bars
all other front components are new OE style.
275-60/15 Toyo 555S rear, 275-50/15 Toyo 555 in front.

Pretty basic, keeping the traditional 15" look.
Will it need bigger torsion bars than the .940"s? I imagine the weight savings from the Borgeson, the 408's aluminum top end, Sanyo compressor vs. the iron V-2 is considerable, but not having the typical B or RB weight in the nose
should be a help.
The shock selection is also up in the air. I have used the Vikings, and Ride Tech, but not Bilstein. Vikings are nice, but the price isnt. Whats the verdict there?
A rear sway bar- wait and see how it feels, or just count on needing it?
Round two for the car will be subframe connectors, most likely the US Car Tool scalloped style with all the adders, minus the rear frame over-axle plates. I dont plan on any type of cage, so the under car connectors will have to do.
I'd love to take it to a track day once in a while, but mostly it will be driven on twisty Country roads, with a few long straights...
Has anybody strayed from the traditional Big Block build and gone High Rev Small Block? This will be my first one, so any experienced thoughts are welcome.
Thanks

 

[Don Frelier]

275-60/15 Toyo 555S rear, 275-50/15 Toyo 555 in front.

Likely a typo here...

I like the 1.03" torsion bars. Even with a smallblock they would still be an improvement.
Definitely a rear sway bar if you like turns.

 

[Belvedere408]

I really like my Bilstein shocks and 1.03 PST bars.

 

[RJ Squirrel]

 

[Brutalowner]

Likely a typo here...

I like the 1.03" torsion bars. Even with a smallblock they would still be an improvement.
Definitely a rear sway bar if you like turns.

Nittos, my bad.
I have used the 1.03" bars in the past, on a b body cop car. It was not a big leap in stiffness for the BB car, So it might be just right for a LA car.
Thanks Don!

 

[Brutalowner]

I really like my Bilstein shocks and 1.03 PST bars.

Sounds like the 1.03 bars are going to be the choice.
Thanks Belvedere408

 

[Brutalowner]

Here is the Charger. Triple Green/318

 

[ckessel]

Your project sounds great. My 67 Coronet wagon will be getting many upgrades soon, like what you're doing, but not as extensive as what I've done so far on my 65 Coronet[ back burnered while I'm generating project money].

 

[Belvedere408]

Sounds like the 1.03 bars are going to be the choice.
Thanks Belvedere408

I also added us car tool subframe connectors and torque boxes. My car is 67 Belvedere with blue print iron headed 408 and 4spd. Has a front sway bar also.

 

[ckessel]

When you go to weld the structural improvements in, make sure the car is well supported. Either on a 4 post lift or the tires/wheels on cribbing. If its on a two post, [unless its a bare carcass no engine, trans, suspension, interior etc], or on jack stands, the body will sag and you'll have fun getting the doors open or closed after you've welded.

 

[snakeoil24]

Skip aluminum drive shaft

 

[Kern Dog]

The .94 torsion bars are weak. These cars were notorious for having soft front spring rates and stiff rear spring rates. 1.0 should be the starting point for torsion bar sizes even with an LA series engine. I run 1.15" bars in my red car.
Years ago, an outfit known as XV Motorsports put several Mopars on a 4 post chassis jig to put these cars to chassis stress tests. They found thatfor improved handling, the rear spring rates could often stay stock but the front needed additional stiffness. They sold sway bars, torsion bars, leaf springs and other stuff. This outfit was a big proponent in chassis stiffening too. Frame connectors, torque boxes, reinforced core supports below the radiator, etc. US Cartool picked up where XV left off and they sell similar stuff since XV folded up shop.
Rear sway bar? Yeah...It needs to be smaller than the front but the exact size may be hard to determine. It would be fair to start with a rear bar of approximately 70-75% of the size of the front. The 1 3/8" front bar you mentioned is probably hollow and that means it's stiffness is on par with a solid bar close to 1 1/4" size. This means a rear bar around 3/4 to 7/8" may be right but it really depends on the configuration of the bar. Longer lever arms on a bar reduce the effective rate of it due to the leverage increase. A 3/4" bar with 12" lever arms will be stiffer than a 7/8" bar with 16" lever arms.
Some might suggest Hotchkis but be ready to spend a lot. They build quality stuff but you sure do pay for it.
I'm the guy that always looks for a cheaper way before cracking open the wallet.
Front end alignment will really make the car respond well when the road gets twisty. You need more caster than the stock control arms can usually give unless all the planets are in alignment.
I was able to get 6 degrees of positive caster with stock upper control arms because of offset UCA bushings and a low ride height. The geometry of these front ends is such that the lower your ride height, the more caster and negative camber you can have. A car at a stock ride height cannot get as much caster as a lowered car.
Here is mine...

QA 1 makes some good stuff. I have their tubular front sway bar and upper control arms. I was able to align mine to 8 degrees of caster and 1 degree of negative camber. NO, this does not result in increased tire wear, just better steering response and control. A new Challenger R/T has a lot of caster too....

 

[RJ Squirrel]

My 68 I just took apart was a factory 318/904 car with the skinny torsion bars. I was relieved to find out that the 318 in it was not the original so out in the scrap pile it went and a 383/727 is going back in. I will be needing to upgrade torsion bars. As for the UCA's, I modified the stock ones in my RR to move the ball joint aft about an inch, which gave me 5 1/2" caster with the *** end high rake I have. I did that mod after test driving a bit, and it was night(mare) and day improvement. I did have offset bushings on them but they did not help much. I highly recommend aftermarket UCA's or modifying them.