Sub frame connectors

That looks really good Malex. Is that a Dart? It looks a little different than a Barracuda but virtually the same idea I used. I welded a piece of plate to to the front of my connector then plug welded the plate to the torsion bar cross-member . I saw one job where the guy left the vertical part of the frame on the outer part of the rail and welded his relocation to that.
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Yep this is my Dart. It's a winters time project. Winter #3 will be coming up here soon and I'll be back at it. The 2 X 3 laid in this way fit great.

In the picture below the 2X3 shows where it comes though. Only at the rear floor section.
IMG_0275.jpg

The driveshaft hoop I did like you mentioned, a flat plate on each end and then plug welded.
IMG_6452.JPG