New Fast Ratio Steering Linkage Kit $239!!!!!!!!

I have more questions. First, what makes this kit NOT able to work with the early (63-66) cars? Secondly, can you say for sure what the ratio would be from a stock 24:1 box using this kit? I'm interested, but I need to know before hand why it will not work with the early cars so that I can see if it is something that cen be overcome. Thanks.