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

Your front torque boxes really don't matter, but the rear are meant to be welded on BEFORE the sub frame connectors. They don't have to be modified to do that. If you install them after you will have to cut them to fit and it makes a weak intersection. I've installed them 3 times now on cars. That's the way it's done (See pic).

The sub frame connectors may have an issue where they start to angle off the floor pan about 18" towards the back, just make a cut on the sides, bend to fit them and weld up the cuts. You goal is to have the sub frame connectors flush and not 1/4" below the rear cross frame.

You will have to relocate the brakes lines and gas lines if you don't want to snake them thru the sub frame connectors.

US Car Tool has several hundred pictures on there site to explain how to fit their products, and they are always available by phone and email.
torque boxes.jpg