Let me tell ya, I dropped the motor/trans/k-frame four times during a two month period hunting down a pretty awful screeching noise. Clearly it was the back half of the drivetrain and I thought I found the culprit the first time I dropped it. Turns out (I'm leaving out a lot of story for the sake of brevity here) that the tip of the input shaft retainer sleeve was just barely kissing the button head of the splined center section on the outer most clutch disc (and I do mean barely because it was only temperature that brought them together). It drove me insane for those couple months. But you can't give up and you can't cut the corner. Better to cry once now than to cry a thousand times later when something goes kablooey.