You have to join the VCCA club forum. It's restorer club for chevys. DON'T tell them you are going to rod it up as they are almost all purists. BUT, youn will get lots of info from them on howtos and where do's.
Also there are plenty of chevy suppliers. One that is dedicated to chevies it The Filling Station in OR.
http://www.fillingstation.com/
http://www.20schevyparts.com/
http://vccachat.org/
http://www.obschevy.com/
http://www.iandireproduction.com/
http://www.aaaparts.cwmax.com/chevyhd.htm

This should keep u busy for awhile!