Check out Year One
http://www.yearone.com/serverfiles/f...sp?cat=W&pco=1

They have virtually every repro part youy mightneed for a restoration
of a GM muscle car (and others) They also sell shop manuals,
instruction videos, etc.

Join a national club for the specific make of your car. Many clubs
have web based help forums,etc. Other GTO enthusiasts will be more
than ready to help you with parts, procedures, etc.