Sub-Frame Connectors

[1970GranCoupeConvert]

I am considering installing sub frame connectors in my Barracuda convertible.

I do not plan on installing a high HP engine or drag slicks or anything extreme but I would like the body to be a little more stiff.

Does anyone have any recommendations of the kit to buy and any experience they would like to share?

THANKS!!!

[Skdmark]

I have a friend who installed the US Car Tool ones his 70 Cuda. Was happy with how they turned out.
http://store.uscartool.com/e-body-frame-connector-plymouth-cuda.html

[Topcat]

U.S Car Tool by far.

They're not plug and play though on installing.

[Skdmark]

U.S Car Tool by far.

They're not plug and play though on installing.

He spent a ton of time getting them to fit snug prior to welding.
If fitted properly, they really blend in nicely.

[Topcat]

My neighbors threatened on me to call the Cops on all the grinding I did to get the welds smooth.
They cooled off once I showed what was happening.

[RUNCHARGER]

I kind of hate them but I can sure see adding them to a convert. Is this a project car? My friend Mike has built some that he installed inside the rockers out of sight. This is a set someone added to my U-code, make sure you figure out where your emergency cable passes through.

[Chryco Psycho]

I just build my own using 1"x 2" .125 wall tube , notching & rewelding the tube at the lowest point of the floor to match the floor profile , use a slightly larger plate at the front to the crossmember by the T bar & match the angle of the rear frame rail & weld them in .
Total cost $30 in materials , probably did over 30 sets of them on customer cars . Park brake cable clears over the top , easy to do  !

[torredcuda]

I usually try to fabricate parts myself or because of budget look for cheaper alternatives but in this case I like the US Car Tool ones. I did the square tubing style on my `69 and they are fine but the USCT not only look more "factory" and they can be welded to the floor the whole length adding a lot more strength. I cut ovals for the brake cables to pass thru.

[torredcuda]

I kind of hate them but I can sure see adding them to a convert. Is this a project car? My friend Mike has built some that he installed inside the rockers out of sight. This is a set someone added to my U-code, make sure you figure out where your emergency cable passes through.

I considered hiding some tubing inside the rocker panels but since my car is just a modified BH Barracuda I wasn`t concerned about looking original, I think that would be ideal for a rarer model I wanted to keep looking stock.

[Dakota]

I used the US Cartool subframe connectors along with many of their other products. They do require a fair bit of tweaking to fit.  As a novice welder, it was quite an education.  Between filling the gaps and learning how to get the weld puddle to move from the heavier gauge SFC metal to the relatively thin floor plan involved lots of trial and error as there were multiple burn-throughs on the floor plan that had to be patched. Between an angle grinder and spiral bits for my die grinder, I ended up spending lots of time cleaning things up.  The end result was good from an appearance standpoint. but more importantly between the SFCs and the other stiffening products my car (not a vert) is really solid now. 

Bottom line: a fair bit to a lot of work depending on your welding skill, but definitely worth the effort.

[HP2]

Any weld in connector is going to improve the rigidity of the car. Even the not so tall ones that don't touch the floor. Certainly those that bisect the floor and weld to it are further improvement, but  nearly anything is better than nothing.\

I've seen improvements using basic, inexpensive, bolt in style with the ends welded instead of bolted.

[1970GranCoupeConvert]

The car is a completed restoration.  I did a rotisserie restoration about 20 years ago so the car is really cherry and that is my big hesitation...I do not want to make a huge mess.

The problem with me is that I have "Might-As-Well-Itis" in that if I am doing a project I say "might as well".

I am installing a Sniper EFI and I had to remove the left side panels and sill plate to run the wire for the fuel pump and the carpet is looking a bit old so I said "might as well" replace the carpet while I am at it...then once the carpet is out I might as well do the subframe connectors...

I watched the US Car Tool video that they have on their home page Us Car Tool | Restorations, Unibody Stiffening, Body in White, Restoration Tools
and I was scared away because the people on the video appear to NOT know what they were doing. Yes I know the video was produced by Popular Hot Rodding but the mechanic in the video must be from Us Car Tool. The narrator guys says a bunch of time something like "It looks like we are going to have to..." The car is on a "two post" lift with the engine and rear axel installed and with the car being suspended in the center the front end and the back end are sagging down and that is precisely what you are not to do...IF...you want your doors to close.

I do like the contouring sub frame connectors because they retain the stock look.

My convertible will sag and the doors will no longer close when it is on my two post lift so I would need to have the wheels holding the weight when I install the sub frame connectors.

I am wondering if the end result in the stiffness will be worth the trouble.

THANKS for the advice.

[RUNCHARGER]

Argh: Looks nice under there but I'm a function first type of guy. I'd be wringing my hands on what to do.

[anlauto]

I say if the factory never used them 

Unless your plan includes any of the following: Super torque monster engine, hard launches with slicks on a prepared drag surface, hard cornering on a road course, I really don't see the need to stiffen up the ride of the car so that it rides like it on bricks. JUST MY OPINION.

I think when planning a build of a car, you really have to look at the intentions for the car and the forecasted driving conditions.

[MoparLeo]

When new, these cars had a fairly rigid structure but after many years of flexing and twisting, even just a little over the years have a cumulative effect on the whole cars structure.
These cars were not built to be around 50 years later and economy of the build was the number one priority.
I would definitely recommend going with more of the number 2 US Car Tool stiffening option kit.
Stiff is good for the car. I will attach a few you tube videos that are very informative on Unibody construction.
https://www.youtube.com/watch?v=Ric5XfDuyAc&list=LL&index=2
https://www.youtube.com/watch?v=IhbXPzPlzNI&list=LL&index=1