FTI TC Anyone run one?

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.

I get it man, but you know you're not the only person through history to do it like this. People have done what you're doing and worked around it. It's even easier now with the modern converter technology. Call a converter company and talk to them. That will be a lot more accurate than this place.