@Ruggtomcat: my Google Fu is weak.. I couldn't find any articles by or about Timothy Ferriss that mentioned changing muscle fibre ratios.
To clarify, did he say changing the ratio of mass of muscle type or of fibre numbers?
I'm properly intrigued, since I had always read that your number of Type I/Type II fibres and therefore their ratio was just about set in stone. If I recall correctly, there were some hints that elite weightlifters might be doing actual real 'fficial myofibril hyperplasia, but that was about it for humans. Animals do it more frequently.