Something else to throw out into the mess is that Ford changed the input shaft from a 24 to 26 spline in 1970. So without some modifications you need to match up the convertor to the year tranny also. Just an FYI.
Update: I went back and got the flex plate, block plate, and engine harmonic balancer, from the same 73' Comet that I bought the tranny and other stuff from. While I was at it....I got the 302's motor-and-frame engine mounts, as well as the original "Powered By Ford" valve covers. Thanks for all of your help Tranny crew!!! Paul: Yeah...agreed...I think when we originally pulled the tranny, the torque conv wasn't unbolted from the flex-plate until after we pulled the tranny, and the shaft fell out when the tranny slid off the torque Conv/shaft. - Roger
All you have to do is slide it back in. Just be sure which end you slide in - the splines are different - one end has 24 splines and the other end is 26. The 26 end goes into the converter and the 24 spline end goes into the transmission.