A friend of mine has a 4L80, controller and torque converter and mentioned selling it to me. I need to replace my TH350 and it's either going to be a 4L80 or TH400 but I guess I'm just not sure which one would suit me better. This is a street car with a 650hp N/A small block and 3.73s. Weighs about 3185 as it sits. I always thought the overdrive would be nice. Who's got an opinion one way or the other? I'm on the fence here.