He was alive on 12/25/08 anyway...
Then there's that other ZX2 guy Darin linked, who did the same thing, and ended up with the same result. I mean, failed gears. This other guy claimed +6% fe, not 100 mpg +.
Looks to me like such a mod is fraught with danger- high likelihood of spending substantial $$ for short lived gears. IMHO if the ratios you desire aren't available in "real" gears and/or you don't get "real" gears made from scratch... it may not work out.