The show "Trucks" did a great series on doing this cut. But here are a few links to other threads on here. The first link is a great one about shortening the frame, second is a general discussion, but the third is a GREAT link with many additional embedded links by lakeroadster and markeb01 even has a link to the Trucks episode (highly recommended). I'm still waiting for the powerblock tv folks to make a complete build dvd for the 66 C10 they did....
http://67-72chevytrucks.com/vboard/s....php?t=123624\
http://67-72chevytrucks.com/vboard/s...d.php?t=186341
http://67-72chevytrucks.com/vboard/s...ght=long+short