Ok, I have gone back as far as May 2007 to find the answer but could not. I finally got my TCI flex plate in and it came with what could be called either a bushing or an adapter. It fits into the back of the crankshaft and the torque converter's nose fits into the female part of this bushing. I am getting ready to install everything tomorrow and was wondering if this bushing is required. I am using a TCI 3500 stall converter. It probably goes on but I hate doing things twice, especially stabbing a heavy 4L60E.