Changing the torque converter couldn't hurt. The transmission is probably on it's last leg with that many miles on it. It would stink to change the converter just to have the transmission go in 10,000 miles. On the other hand you may get 100,000 out of it. It would break up the cost though. $1,200 to $1,300 spent now will be that much less to spend later. It's a tough call. Driving style has a lot to do with it. Personally, with your upgrades, I believe your transmission is not long for this world. I hope I'm wrong. Good luck