Any tips on fitting the US Car Tool Sub Frame connectors?

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Graminizer

Graminizer

The "Big G"
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Hey guys,

I just received the duster/dart sport sub frame connectors from US Car Tool. They look to be very well made. Right now I have the car on a rotisserie, so I will not be doing any welding yet. I will wait until the car has the suspension all installed. My question is in regards to fitting. How much did you guys have to grind off to get them to fit? The rear drivers side doesn't seem to want to line up....the front seems much better....any tips would be great...thanks.

Graeme
 
Hey Graeme,

I recently installed the same sub frame connectors. I suggest you install them before any suspension components. Make sure to align the holes for the handbrake cable and gas lines to where you wish them to go. You will also have to dolly the floor pan a little as well to get the proper fit. It took very little grinding to get mine to fit and were a great addition for adding strength to the car. I also installed the torque boxes front and rear which I strongly recommend if you are adding a lot of extra power . My only mistake was that I didn't install their lower rad support as well. I already had bought a new one from AMD and didn't know about it. See members rides," Supercuda's Back" for pics of my install if you wish.
 
I just finished the initial fit up on my 73 Dart Sport project. I had to do a bit of cutting to clear the e-brake cables on both sides. I also have to reroute the gas lines on the passenger's side. I had to do about 6-8 fit-and-remove on each side to trim off small pieces of each one until I had a decent fit. I also had to split the channel on each side in the rear as they would not fit over the existing frame rail. I used screw-adjustable jack stands on each end to jack them in position. Take your time, cut it a little at a time, and when you're satisfied with the fit, tack each end to hold it in place until you're ready for final weld. To see what I ended up with, check out the last photo in my restoration post: 1973 Dart 340 Sport Project
 
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use floor jack to hold them in place, i also ground down some places to better fit the floor contours. also bevel the edge you are welding so its closer to the floor pan metal thickness, will make it easier to weld.

i drilled extra holes for welding surface area were it slips over the rear frame stub. they make a great product, you will be happy you installed them,
 
It just seems that they are labelled incorrectly....the L should be the left side (driver) but the R one almost fits better on the left side......
 
Here is what I did.

Take a piece of cardboard and trace the contours of the connector itself, then cut it out. Hold that piece of cardboard up to the floor board and trim the cardboard a little a time, until you get a solid fit.

Then transfer the card board template to the connector and you will know where to grind to make the connector fit snug. Hold the connectors up in place with a few bottle jacks. Here are few pics of my installation.

I also had my car on a rotisserie. What I did was lower the frame down on jack stands and made sure the doors opened easily, and checked the rocker (inside of the door) for level. Once you are there, tack them in place and then you can roll the car around to get a better weld angle.

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This is what I am talking about......This is the drivers side......both the SFC and the spring box are marked with the L, so that tells me that these should be the same side
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But the cut outs for the floor bead rolls look like they are backwards......I had to trim the inside of the SFC for these bead rolls but the outside of the SFC has these cutouts that are not required????
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Graminizer said:
Hey guys,

I just received the duster/dart sport sub frame connectors from US Car Tool. They look to be very well made. Right now I have the car on a rotisserie, so I will not be doing any welding yet. I will wait until the car has the suspension all installed. My question is in regards to fitting. How much did you guys have to grind off to get them to fit? The rear drivers side doesn't seem to want to line up....the front seems much better....any tips would be great...thanks.

Graeme
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Using jacks to hold them up works great. Once I had them fitted rather closely and spot welded into place, I took a large rubber mallet and massaged the floor downward to close the remaining gaps. Don't be lazy and avoid the required grinding or get carried away, but this technique is virtually undetectable once they are fully welded in. I also reversed the polarity on my Mig and used a stich welding technique to avoid puddle sag and burning through the floor.
 
When I bought mine for my 65 Dart, I was told by friends to get the chassis on the stands on a level level level floor, also, I checked the height of my jack stands (a.c. delco) to be sure they were all the same height while supporting the chassis. Definitely not on the rotisserie until tacked securely in place. Be sure front and back of the chassis are resting and are supported in the same place...right and left side....then use the door margins to see if the chassis has any twist. Yes, jack the connectors into place from the bottom, but do not over jack where the chassis is off the supporting jack stands, and with the carpet removed (fire), weight the inside of the floor pans to push down a bit. A bit tight with the jacks, and a bit weighted from above, then scribe and cut/grind to fit. A proper door margin all the way around, i am told, will determine any chassis twist. Having the front suspension on or off does not make a difference based on instruction I rec'd from USCT....I think off is better. Not an expert, but hope this helps you out. Old Dart 66
 
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I agree with most of what's been said so far. I installed these on my '71 Dart, they definitely required some grinding and fitting. I probable test fit each one at least half a dozen times, grinding and fitting in between. I installed mine with the car up on jackstands at or near the suspension points, and I used a bottle and scissor jack to hold them in place while I fit them, checking the door gaps etc when I started welding. But that said, I have seen these connectors installed while the car was sideways on a rotisserie, upside down on a rotisserie, you name it. A bodies, E bodies, whatever. I have yet to hear of a single case where someone welded in a set of these USCT connectors on a rotisserie and then had issues fitting the body afterward. I'm not saying that it's impossible to weld the connectors in and warp the chassis, but I've seen dozens of installs via the internet that were done while the car was on a rotisserie, some being very high end restorations, and I've yet to see a car that had body fit issues because the connectors were installed on a rotisserie with the car flipped to allow for easy welding.

I will also say that it is a royal pain to weld the USCT connectors in while underneath the car. If I had a rotisserie, that's how I would install them. I'd lower and level the chassis out, use jacks to push the connectors against the floor and do all the fitting, check the door gaps and stitch in some welds at the ends and a few in the middle. Then I'd raise the chassis up on the rotisserie and flip it so I could finish the welding with the puddle below me instead of above me.
 
Welding overhead is definitely a pain, especially when the thin floor is above and the thicker SFC is below, and you want to carry the heat on the higher surface. I envy those guys with a rotisserie so much!
 
There is a video on YouTube that shows the installation process. The video is called "How To Install Mopar Subframe Connectors" by Popular Hotrodding. They are installing Reilly Motor Sports SFCs, but it appears that they are close in appearance to USCT. Pretty much step by step. Regarding the welding, they show the bead starting on the SFCs, and working the bead and heat into the floor metal. There are other videos there as well. Just a thought on what I found while installing mine. Hope it is helpful. Old Dart 66, Jerry
 
The only issue I had with the subframe connectors was about 16" from the rear they started to spread away from the rear floor pan and had about a 1/4" gap at the rear torque boxes. I just cut the connector at the 16" point, bent it up to hit the floor flush all the way back to the torque boxes. Then welded the cuts on both sides of the U-shape.

The other issues were rerouting the brake lines and re-routing the gas lines. Which you should upgrade to larger anyways.
 
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I did mine on the rotisserie. I knew the shell was square & straight and I didn't have to deal with overhead welding. I remember something funky about the fit, but I also didn't care for the way they ran across the floor. The rear frame rails are farther apart than the front and they're designed to connect at those points. I didn't want mine welded in at an angle so I had to modify them to run parallel to the rocker.

Totally worth it. The shell is so solid, it won't sit on jackstands when the floor is uneven-it won't contact the stand on a low part of the floor.
 
Does anyone know if Us Car and Tool gives FABO members a discount like most of the vendors on here?
 
WymanV said:
I did mine on the rotisserie. I knew the shell was square & straight and I didn't have to deal with overhead welding. I remember something funky about the fit, but I also didn't care for the way they ran across the floor. The rear frame rails are farther apart than the front and they're designed to connect at those points. I didn't want mine welded in at an angle so I had to modify them to run parallel to the rocker.

Totally worth it. The shell is so solid, it won't sit on jackstands when the floor is uneven-it won't contact the stand on a low part of the floor.
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Im having the same issue with my Dart....how did you modify these to make them run parallel ?
 
Alot of great ideas here to get them to fit nicely. And informative pics.
 
I put mine in at the angle recommended in order to tie the front and rear front to back frame rails. Mine are shown in photos on my rebuild. I am Old Dart 66, and my rebuild thread is named 65 Dart Revisited, under members restorations. Best of luck on the install. There are some videos on you tube that show the process. Best. Old Dart 66
 
Old Dart 66 said:
I put mine in at the angle recommended in order to tie the front and rear front to back frame rails. Mine are shown in photos on my rebuild. I am Old Dart 66, and my rebuild thread is named 65 Dart Revisited, under members restorations. Best of luck on the install. There are some videos on you tube that show the process. Best. Old Dart 66
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thanks for the info
 
Dragnut said:
thanks for the info[/QUOTE

Yes, those videos on YouTube give a very detailed step by step description. The video is relatively short, so, for the time spent in viewing, the time is well spent. In particular, keep an eye on your door margins as any body twists, that can/might occur, will alter these margins....especially on a HT. Simply, jacking the car, moving the floor to fit the connectors, and etc, can create some problems for door fit. I was advised to remount my doors during the fit and the tacking in place, and keep a close eye on those margins as the connectors are tacked in place. Maybe I went a bit overboard, but like the old adage, an ounce of prevention is worth a pound of cure. I could not imagine cutting those things out due to a movement of being squared up. Hope this helps some. Old Dart 66.
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Installed a set a month ago. They are nice, but a PIA on a 45 year old car with undercoating....and (IMO) overkill

Next time, I would simply make my own for the shipping costs alone. Rectangle box 11ga tubing on its side UNDER the floor with a little notching at the rear attaching area will more than do the job without even cutting thru the floor. I personally do not care for utilizing the floor as the 4th side by welding the thin gauge floor sheetmetal to the larger gauge connectors.

The California Flash has nothing more than 1-1/2" round tubing under the floor pan connecting the front and rear frame rail. Hundreds of 150 MPH runs (3 Wallys) with the wheels up....and NO twist what-so-ever.

Cheap to build, simple to fab, easy to install, and effective......Win, Win,Win,Win!
Simply my opinion, yours may vary.
 
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x2 on Denny's post. I went with 3" x 1.5" laid on it's side. Easy peazy & $36. That said, once you get your set installed, I'm sure it'll be awesome Graminizer.

Looking forward to following your build!

Pat
 
HemiDenny said:
Installed a set a month ago. They are nice, but a PIA on a 45 year old car with undercoating....and (IMO) overkill

Next time, I would simply make my own for the shipping costs alone. Rectangle square tubing on its side UNDER the floor with a little notching at the rear attaching area will more than do the job without even cutting thru the floor. I personally do not care for utilizing the floor as the 4th side by welding the thin gauge floor sheetmetal to the larger gauge connectors.

The California Flash has nothing more than 1-1/2" round tubing under the floor pan connecting the front and rear frame rail. Hundreds of 150 MPH runs (3 Wallys) with the wheels up....and NO twist what-so-ever.

Cheap to build, simple to fab, easy to install, and effective......Win, Win,Win,Win!
Simply my opinion, yours may vary.
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I agree..AFTER purchasing these I saw what some other guys where doing for frame ties and thought I should have researched it further before pulling the trigger on these, but I have em and there going in....
 
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