91 Ford F155 57\" springs a great fit! I found a 1991 Ford F155 (designated such by the sticker in the door jam) with the 4 leaf + overload in a local junk yard. The spring pack only needed to be redrilled and installed with no extra leaves and it rests at the same height as a stock set of springs off a k5. The ride is much smoother than the 3 leaf + overload f150 pack with k5 leafs mixed in and feels firm but glassy smooth. It feels so smooth that the front end seems rediculously stiff. I know there were a lot of questions recently on which packs to get, so I had to post my trial and error succes. Thanks Marv, good advice on the target!