The torque converter is straight forward but time consuming to change. In a Celi, the easiest way is to unbolt the motor, snug it to the firewall on th opposite side & that will give you the room to slide the torque converter off.
A friend had a stall converter in his Montecarlo, it was definately cool. You jam on it, it revs up and then finally starts transferring the power to the road. The first 50 feet were pretty amazing.