United Car Tool Torque boxes - can they go in AFTER subframe connectors?

So it doesn't sound like you're contradicting 72Blu's comments except that you have found that it significantly weakens the joint...which presumably defeats the purpose of the connector to some degree...

You will find out that the sub frame connectors, will in most cases, be too far away from the rear cross frame to be installed first... The pic below IS from the US Car Tool website... In the picture he posted, the sub frame connectors won't land that close to the rear factory cross frame. there will be a gap. That gap can be as much as + 1/4".

The OP was asking for the ORDER to weld them in. I've done it 3 times now. The torque boxes were designed to go on first.
torque boxes.jpg