Story came up this past weekend about the dual idler system. You only need a single idler gear for it to work, but the second idler gear is only there to keep the first gear in mesh otherwise it would fall out. The other story was that Jackson, hearing the noise the gear-set made, spent a buttload of money playing with the tooth pattern and mesh to get them quite , but had no sales of them because everybody wanted the noise (at that time). For most young hotrodders it was the first "internal" engine part that they could change without complete teardown