When I found mine,I went to a Monroe parts catalogue identification guide that shows the configuration and all shock specifications (including overall length,mounting attachments,etc). I looked over the shock for the Impala application,then found similar design but longer overall length. The shock I used was for a Cadillac,,but I cant remember the actual year,etc. This was a while back,,when most shops still had a catalogue rack on their counter,not an on line set up.I'm sure a reputable parts house could help you.