Frame connector question

[truckinman466]

I have a set of usct frame connectors I am putting on my Challenger. I am doing a rotisserie restoration. I currently have the car sitting on a set of usct car dollies. Can I weld these in before I get to the paint stage. I have the doors and quarters all lined up.  I've heard different opinions about this. Has anyone installed these under the same condition as I have?

[Chryco Psycho]

You should be fine,  the load on the body will be i nthe same place as the suspension & you have all the panels lined up

[jimynick]

I'm a bit confused; is the car on the rotisserie right now or are you going to put it on to do the SFCs? If it's on the rotisserie, it's not suspended the same as it is when on it's wheels and I'd take a good look at those gaps to see what, if anything, happens when you've got 'er hanging by the subframe rails. I put mine in with it on the rotisserie before trying to align sheet metal. Be prepared to either hang and scribe the SFCs or do what I ended up doing and hold/mark/grind/refit until you get a good close fit. They're not bad, but certainly not a direct weld-in part. I don't know your welding skills and as such, will suggest starting your MIG arc on the thicker SFcs and wash it onto the thinner floor. That worked pretty well and you'll like the stiffness improvement as well. Are you also installing their torque boxes, as well? 

[truckinman466]

It is not on the rotisserie right now. It's on the car dollies. And yes, I'm putting in the torque boxes too

[Chryco Psycho]

for extra stiffness you can add the support strut above the tire in the wheelwell from the cowl to inner fender , also add the stiffener under the rad & weld up the K frame with extra supports too .

[Topcat]

Some people have said you must have full drive train in place to "Load the frame"  before putting in U.S. Car Tool connectors.

Poppycock.   

Use 6 or 8 Jack stands and make sure the vehicle is super level. (Or as best you can)

Did that on mine and it came out fine.

[Dakota]

I had an email exchange with Chris Lewis from USCT in December 2015 on a similar question about installing the subframe connectors.   This was part of his reply:

"The motor is not required to be installed to weld our frame connectors in place, in your situation you need to support to the frame of the car by the suspension mounting places in the front and rear. The idea is to keep any excess weight from hanging off the car."

I also sent him the two pictures below to show him where I had the car supported with orange jack stands before welding in the connectors.   He said the placement was fine.  Unfortunately I don't have a better picture of the placement on the front jack.   The silver stands were used to hold the connectors in place while checking fit and before the connectors were tacked in place.  These stands were very easy to adjust.

I've since added the drivetrain to the car.   The doors still fit and close fine.

I had the USCT inner frame braces installed before the car was painted.   I've since added the torque boxes and core support stiffener along with the subframe connectors.   It's definitely better to do all this before the car is painted.   As noted by other members, there's a fair bit of time needed to tweak all of these parts to fit before final welding.