To get more range of motion on the barbell T-Bar row, replace the standard V-handle which can limit your range of motion and lock in your scapula. What you want to do is get those elbows further back.

Attach two free motion handles together and use that instead. This will increase the range of motion. Squeeze each rep for a second at the top of the movement to really light up the target muscles. To get even more range of motion, load up the bar with 25's instead of 45's.