I believe those that say 60-62 GMC had bolt in rear seats, 63-66 had the tracks may be correct.
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/image3.jpg[/IMG]
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/image2.jpg[/IMG]
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/DSC03484.jpg.hyml[/IMG]
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/130440_400.jpg[/IMG]
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/145630.jpg[/IMG]
[IMG]http://i279.photobucket.com/albums/kk158/bartamos/jantzen_jim_1963_03.jpg[/IMG]
Above are 1963-1966
Here is a 1960 GMC floor with key holes.
http://i234.photobucket.com/albums/ee278/Corts76/SDC16284.jpg
Lots of confusion about this. If Tony has "later GMC's" with key hole. I definitely had a 3 year old 1966 GMC Carryall with tracks. Did we catch Chevy and GMC swapping left over rear bodies with appropriate front clips, horn button, etc? Yes, they did have keyhole GMC's and Track GMC's, same year.

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