So the car is still "drivable," runs through all gear to what I can tell. However, it will make a slight whistle noise when under a decent acceleration. as if the supercharger was faintly Whining. Any further acceleration and the transmission will start to make a horrendous grinding sound as if the engine is spinning and the trans isn't. (Builds up from slight whistle to grind as if a chunk of metal is in the torque converter) It also occasionally pulsates when under acceleration. I do understand this transmission is probably ****, but I might replace is and keep this one to tinker with to understand it better and maybe fix or build a better one.

My question is what parts are bad?

I'm assuming the piece that connects the engine and trans is what's making the whistle and grinding.

And I'm also assuming the reason why its slow to shift gears is a solenoid, sensor, or the control unit.