Looking into putting a 700r in my project truck. I put one in my father in laws 51 ford because the one in it was smoked when he got it. The rebuilder told us not to worry about the lock up torque converter not locking in at high speeds. He gurantees his tranny. The guy at the local tranny shop said not locking in the torque converter will ruin the trans and need a dummy converter. Both professionals with opposite opinions. Whats the real story?