Big T8993

When dropping off truck, GMC ran the codes right there and pulled a torque converter. Surprise surprise. Day later, need a new trans (reman) with a $5700 price tag. Now I know the price is fair enough for a dealer. I also know the track record/law suit battle with GMC trans. My question is more of what else can be done to help the new reman transmission I'm having put in my truck?? I've heard things about a billet kit or some sort of updated transmission bypass valve/thermostat that will help. Any truths to these thoughts??