Hey 53
I just read about this very thing today on another forum. From what I gather, the best quality based on the photo in the thread is from a company called Tabco. Unfortunately they do not handle our older trucks. The second best is Tri-Plus which is carried by Classic Parts. If you'll see the first cab corner he has in the photo, it is awful. I guess there is a difference. I was always under the impression that the same place made them and we all choose where to purchase based on what our favorite place to buy from is. Anyway, hopefully this helps you decide if you want to do the JC thing or not.
Here is the link:
http://67-72chevytrucks.com/vboard/showthread.php?t=630393Good Luck