I have an 8" Turbo Action 4500 converter in my car. It has seen 5 drag weeks and is about 16 years old. I do not run a temp gauge, and going down the highway on drag week the car is about 4100lbs with two occupants and cargo. I haven't changed the fluid in a very very long time and it still looks and smells fine. I am sure it could use a freshen up soon because it does drain back when the car sits for a week or so but it is still performing well, I got a new best 60ft last weekend.

There is guys on drag week that run 6000+RPM converters and pull a trailer. I worry about mine a lot less after seeing some of that going on.