I found that using OEM GM pins and bushings was the only way for me. The Dorman pins are too large in diameter and require reaming out the hinges.
Here is my experience with replacing the pins and bushings. I did not have a engine hoist to hold the door up so I just built a platform out of 2x4s - worked well for me.
http://67-72chevytrucks.com/vboard/s...ubba+door+pins