For those wondering the post with the idler pully drawing is here
http://ecomodder.com/forum/showthrea...tml#post187726 .
Here is the routing path
http://ecomodder.com/forum/attachmen...4&d=1282265119
I have not seen the idler that you are using but try flipping it over so its out of the way, on a pulley that large you should not need to worry about belt slip. Looking at the drawings linked above the two plans for routing will have about the same wrap. Also to me the idler pulley looks like its purpose will mostly be to keep it from rubbing any thing else in the engine.