or
http://www.lingenfelter.com/mm5/merc...3#.UmXO8_mgnQY
Probably a little easier than swapping the crank.
Edit; this only works for the down conversion, so running the GenIV wiring in an older setup.
What are you trying to install that requires a 24x reluctor? That would mean your currently running a NNBS truck, or GENIV wiring, but installing the older ls series into the truck?
Help me understand here a bit.
Otherwise; yes, swapping the crank /crank tigger etc would be the result.