I just shot my 67 GMC with a suede black from Endura. A really nice flat black is made by Sikkens and is called Rally Black. If you want to go economical, you can get some John deere Blitz Black and shoot it on.

This is John Deere
http://www.vendettas.cc/images/pics/bulldog.jpg

Sikkens
http://67-72chevytrucks.com/vboard/a...id=72777&stc=1

And my 67 in Endura

http://67-72chevytrucks.com/vboard/a...id=80290&stc=1