FTI TC Anyone run one?

Certainly you wouldn't have to for every single mod. That's just dumb. What I would do in your shoes is call a converter company and tell them what you have in mind. See WHERE they would draw the line at either choosing another converter or changing what you have. I bet you'll be surprised.
for example, I'd like to go another round with my low dollar 318, but I may pull it and slam a aluminum head 440 in it.