Sweet drop kit for 67-72 C-20

[Jon Yaffe]

Hey guys,
I just registered for this site today; let me tell you, it's sweet. I have been looking for a good 67-72 truck forum for at least a year. I just found this place; what a blessing. Anyway, I wanted to let you C-20 guys know about a sweet breakthrough. I am currently developing a drop kit for 67-72 chevy/GMC 3/4T 2WD. I have been working on this for about 7 months as an independent study to recieve my master's degree in mechanical engineering. It should be entirely built and tested by this August. I am also hoping to start my own suspension design company by next year, and this should be a good start. I have been unable to find anybody that builds an entire kit for these trucks, which does not replace 3/4T components with 1/2T stuff. If anybody is interested in the specifics please let me know; however, I write this post for a more important reason.
I have been trying to research some weight ratings for these trucks, and GM won't help me. Can anybody can supply me with the following information: what is the factory payload capacity and the factory towing capacity (camper's special, or any big block/manual tranny)? Any good estimate of these would be appreciated. There is one other request; I am also looking for the factory curb weight of these trucks. I have measured mine to be about 3800lbs, but that was without a bed, and I don't really have the means to measure the weight of the bed. Even better, would be if anybody has placed scales under each tire to get an accurate weight distribution of the truck. I am currently working on trying to measure this, but a quick response would certainly help my efforts.
Thank you for all responses. I look forward to being a part of this awesome website.