 They let you (re)use idler pullies in different locations depending on your need. Years back the lower idler pulley had a list price of nearly 2x that of the upper unit. The only difference between the 2 was the lenght of the mounting shaft. These let you use the (at the time much) cheaper upper unit in the lower location. I still have 1 or 2 in the garage I think in the back of the tool box but they are pretty much obsolete now since Nissan leveled off the price of the lower pulley to that of the upper one.
 Bernie Bilski berniebilski@cox.net 1995 Nissan 300ZX TwinTurbo in Cobalt Green 1997 Nissan 240SX SE in Ultra Red ZCCNV #390 ~ ECZA #368 |