60-62 are in a class of themselves, different frame structure.
markeb01 who is a member here has has a good thread on this.
http://67-72chevytrucks.com/vboard/s...d.php?t=369663
and this is a good thread to go threw for info. it is up a little higher on this page
http://67-72chevytrucks.com/vboard/s...d.php?t=450021
welcome
ron