Can anyone tell me where I can purchase the dash clips for the dash pad as well as the screws that connect the dash pad to the dash as well, for my 72 chevelle

here is a link the should be your answer, I have ordered from them and they have a good selection of what you need.

http://www.amkproducts.com/

May try Hinshaw's. They have almost anything you need and very nice people to deal with.