Truck26,
the Vintage Chevrolet Club of America (VCCA) is a great source of information for you, for your truck. They have experts for all the old models cars and trucks. Their member's monthly magazine has a list of people to consult and they have one assigned to your year of truck. In addition, their website is very helpful and it puts you in touch with their members. I have received some great advice from them when I needed it.
