BEST subframe connectors for a 68' charger

[black68]

I've read through a lot of threads on here about which subframe connectors people have used or recommended for the 68' charger. It seems the XV and the US ones seem to be mentioned and used the most, is this still the case?  Has anyone found anything better?  The XV and the US are " U " shape not solid square stock and need to be welded the full length, is that worth it or should a square stock style be used?  I just don't want something that hangs to low. Thanks for any help.

[NHCharger]

Heres a couple of pics of the US Car Tool frame connectors. As you can see it is cut to fit to the bottom side of the floor. I replaced both front floor pans on my 68 before installing these. They only needed slight modification to fit and as you can see do not hang down lower than the rest of the frame.

[myk]

I bought the ones from Mopar Performance.  Those units aren't too popular around here but after welding them on I know my Charger is better for it.  The units posted above look like a great idea but there has to be at least a moderate amount of working the parts over to get them to fit the car...

[Mike DC]

             
There's no need to make the fit perfect along that whole length. 

You would want a bunch of welds in place to add some rigidity and keep the floor from rattling against the connector.  But there's no reason it has to be the kind of perfect no-gap airtight fit you would do with seaming a quarter panel on.  There are already several big round holes on the underside of the connector. 

   

[myk]

Hmm...didn't know that...

[bill440rt]

MP ones here.
Worked for me.

[NHCharger]

Yes, Mike is correct. After 40+ years of abuse no two cars would be exactly the same. I spent about an hour or so on each connector to get it pretty close. There are some holes in the bottom to let any water drain out. On the one I have pictured on the table the slots are for the rear brake line, so you can't fill those in incase you need to replace the brake line in the future. Before installing on the car I coated the insides with a layer of SEM rust inhibitor.

[v21hemicharger]

To me, the Hotchkis style seems the best since they mount to the spring hangers and to me does what a subframe connector and torque box does all in one.  I build my own like theirs.  Mike

[cdr]

US car tool on mine,and their torque boxes.

[HPP]

It seems the XV and the US ones seem to be mentioned and used the most, is this still the case? 

I think this is because they duplicate most closely what an OEM installed frame peice would look like. Because of their smal cross section at the rear, they are not necessarily the most effective, but they are the best at looking original.

The best functioning style connector would be a 3" tall version that bisects the floor and allows it to be welded to the connector. The reason why these would be best is because the function of a sub-frame connector is to resist bending beam motions of a drag launch. The 3" tall height is most reistant to this motion, and putting it into the shear lane of the floor creates greater rigidity that a 1" tall version that suits under the floor.

However, with that said, even a simpe flat 1x2 thin wall, bolt in version is going to produce significant gains in chassis stiffness over nothing at all. After 40 years  of abuse, these cars need all the help they can get in that department.

[HeavyFuel]

US Cartool



*EDIT*   The torque boxes are from Auto Rust Technicians.   

[myk]

Torque boxes, eh?  I like it.  Now, did I just miss it or do many of you guys (especially the "G-Machine" crowd) have these torque boxes installed?

[RIDGERACER383]

What are the torque boxes for exactly?

[Finn]

I have the TQ boxes. And frame connectors.

The TQ boxes tie the rockers to the subframe. Usually used on hemi cars and other b bodies convertibles I think.

[RIDGERACER383]

Oh ok that makes sence.

[Mike DC]

   
Torque boxes were one of the reinforcing additions that the factory normally used on convertibles.  They added it to the hi-po cars even with steel roofs in order to stiffen them up a bit more. 

People think of torque boxes as a Hemi car thing but I think they correlate better with the manual tranny R/Ts than just Hemis.  You can find automatic Hemis without them and 4spd 440s with them.  The factory didn't entirely stick to a pattern. 

[myk]

Gonna have to add these boxes to my 'mod list...

[Troy]

A plain old 2x3" rectangular tube between the rear rails and the trans cross member is enough for a street driven car. Basically, notch the back end to fit the curve of the rail and make a flat plate to weld to the cross member. There will be a gap between the upper side and floor but it will hang no lower than a factory rail. I made up 3 sets of these for my cars a few years ago but installed the fitted kind instead because they have a more "factory" look. I also think they provide more support because they tie more of the car together but the good ol' straight bars have been used for many years and work perfectly fine.

Troy

[tan top]

Torque boxes, eh?  I like it.  Now, did I just miss it or do many of you guys (especially the "G-Machine" crowd) have these torque boxes installed?

fitted torque boxes front & rear on mine  &  hemi only rear leaf spring shackle mounting reinforcement plates & frame connectors 
 

[Dino]

I don't have any of that fancy stuff, I like my body to flex in turns.   

As fun a drive as this car is, come resto time it will get all the beefed up goodies and then some.  I may not ever install the rear sway bar though, the car's butt is inclined to drift enough as it is.