I got it up & running on the 10 ribs, definitely an improvement but not there. The 10 rib belt is either so much stiffer or slightly smaller, I had to mount the ribbed idler higher up to get it to tighten.
I decided to give the next easier pulley (3.12) a try though. Vortech has one called a "tall offset" which Vortech themselves could not tell me what that meant technically, so I decided to order it up and see for myself.
