old truck history?

[CUDA8U]

I have always loved 60-72 muscle cars and chevy trucks,I have a few fords I like ,65-70 mustang fast backs,68-71 mopars,chevy but I do own a 70 challenger and have studied mopars extensively and their history,a VIN or fender tag will break down every detail of the car in question,a simple search will tell ya how many cars were built with great detail of options and production numbers.I have seen many posts on here "including mine" asking about production numbers,color options, specifics yr to yr etc but the info doesn't seem to be as well documented for chevy/gmc trucks....am I wrong on this?