The song was released almost a year before UTF-8 was first presented at USENIX, so I think it is reasonable for the lyrics to be expressed using the commonly available technology available of the time.
For lyrics, you should just transcribe the pronunciation, eg "six foot two".
I for one would impose metric... it may be harder to rap, but true talent steps up to a challenge...
"But I would walk 804 kilometres,
And I would walk 804 more,
Just to be the man who walks a 1,608 kilometres,
To fall down at your door..."
It's so catchy! Perhaps: "16093.44 meters high" by "0.2286 meter nails"...
1.608 megametres :^)
The units are not spoken, but for clarity they should be notated in the lyrics.