Is this good or not? So I was looking for an idler set and I have a couple questions. I did some searches but didn't find any answers. My first question is do I get the 90mm or 100mm? I understand with the 100mm idlers there is more surface area on the pulley but is that really it and worth it? I don't want to have to buy a new belt. Also I was looking at billetflow and divisionx, what do you guys recommend? I noticed the divisionx has dual ball bearing, is this necessary? Sorry that was more than a couple questions. I have a 2.9 whipple with 3.5 pulley and all other pulleys are stock.