If your truck had a 700r4, you won't have to move the crossmember or change the driveshaft. Straight bolt in. The dirty dingo mounts will allow you to put it in the right location.
The truck intake has an unused vacuum port you can use. I've attached a picture.
You can mount the dbw pedal assembly and make it work, or you can do a little fabrication and attach your original pedal to the electronic module for a factory look. Check out Glock's project Fred for the pedal info:
http://67-72chevytrucks.com/vboard/s...light=5.3+swap
Here's a post I did on retaining A/C using the R4 compressor without spending an arm and a leg:
http://67-72chevytrucks.com/vboard/s...d.php?t=724060
Mike