Where can I post my 81 GMC HotRod for sale????not sure whih forum would be correct. thank you in advance

Well, it looks as if you have just posted it here :)

Try here, too, http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=1269

EBay will give you a much wider audience and that translates into a successful sale providing you don't over price it.