Hey LXnSHO, great question.
There isn't really a sub frame. I used QA1 A-arms with 2005 mustang spindles, pkb brakes, and made the coilovers, mounted to spherical stainless bearings. It was patterned after a mustang k member, but just ended up fabricating the mounts for everything into the tube chassis. The rear end was out of a Grand Marque sedan. It has disk brakes. I swapped out the gears for a set a friend had, 4.11s. It's a tight budget build so I have a spool in it due to cost of a locker. After shortening the rear, I had a set of Strange axles made and drilled. The four link is scratch built using cm tubing and heim ends.