I'm trying to create something that did not exist in nature. What I need is a fan belt idler pulley (1/2" wide at the top of the V) and bearing assembly. The adjustment slot in the bracket I came up with is 3/8" wide, so the support bolt/shaft size is limited. 3" pulley diameter would work. I just got back from the local Bearing Agency... the only thing he could come up with was a standard pulley which I would have to machine to accept bearings. This is beyond my meager capability here at home. Looking for suggestions and/or advice.