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

This is an interesting article. They use 3M structural adhesive to bond the connectors to the floor instead of welding them. Super solid and pretty innovative.

Don’t Drop In A Hemi Until You Do These 4 Chassis Mods! - Hot Rod Network

The subframe connectors were still welded in. They glued in the floor pan patches and torque boxes.