This may come in handy for some people, i know it had me stumped not so long ago, but here is a photo of where to find the RPM signal behind the instrument custer. on the shown loom, there is only one wire that is around twice as thick as all the others (white one) - and thats the one you want. You can see which one it is in the photo because i had just twisted on the rpm feed wire for the RSM. Hope this helps someone. (thanks to Liberate for explaining it to me!)

http://img65.imageshack.us/img65/256/dsc00137sd3.jpg

thats all good man

Anyone know if this is the same for 1st/2nd gens?

It is for the first gens, so I would guess true for the second gen as well.

Sweet! 6" Monster Tacho here I come!!!