Listen falcon67, I really appreciate you posting the diagrams of the various C6's. I tried to find them myself but had no luck. I did find what I wanted yesterday and it will be delivered to my tranny guy in the next few days. Here's a pic and it's out of a 1966 thuderbird that had a 428 in her. I also included a pic of my 1964 Falcon sprint to a fellow Falcon owner. Thanks for your help as well as to the others.
If that trans is original to the car it's going to have a green dot valve body, which is '66 only. You need to source a '67-up VB; I'm pretty sure the one in the SB trans you already have will work. However, that orphans the rest of the SB trans, which somebody with a 351 might want.
Fun, huh? Get the FE trans apart and throw out some casting numbers from the case and the VB, and take it from there.