The Seat Handle Lock Return Spring Classic Parts sells appears to be the one that assists with the latches that lock/release forward/rearward motion of the seats in the tracks. The correct GM springs for the seat adjuster latches (1 for the left track and 1 for the right track) from what I can tell is under Parts Group 16.682, GM# 3685105.
Its listed as having a 7-11/16" free length (unextended length).
Your Master Parts Reference is for the passenger car seat and components. Parts Group 16 applies to trucks.
Looks Like Classic is only showing 1 in stock where you need 2.
FYI the picture below is a screen grab of a set of Dynacorn repop seat tracks that show the springs on both tracks. Just for visual reference. You might take a look at your local hardware stores like Ace Hardware, etc. that frequently carry springs like these and take your tape measure to see what you may find.
