Without a doubt, Power Cleans off set pins. Or two heavy reinforced boxes. Try 7-10 reps of 3 or 4 sets. Ever get the chance to be near Olympic lifters, check out the extra thick upper backs. Even guy's in the lighter divisions are dense in that area. Pull's are one of their core movements. Try to keep the upwards motion of the bar close to the body at all times.
Hi-Pulls are another superior exercise for the upper back area. These two exercises will also influence the posterior delts very well. They both are also learning exercises, so a little practice and correct form will be required at first. Might also include, if you wish, shrugs using a trap bar or heavy DB's. A 'T' bar use would be very limited to give anyone that impressive and rugged power look of a thick and full upper back. Good luck.
