Have 67 Firebird with Both R&L Traction Bars, looking to purchase both R&L Plates that go underneath rear seats to secure bars underneath.  Anyone have or no where to purchase ?

moved to proper area. 

and when our classic experts are online, they would be happy to help.

OK I am confused by the question. A '67 Bird has rear leaf springs. Most traditional traction bars I know bolt directly onto the leaf spring itself and not thru to the unibody itself. So I am not certain:

A. Why you would need to drill holes into the body and secure it in the first place?

B. Can't you fab up some generic plates out of mild hard steel for this - assuming you need to do this?

C. Since the Bird shares its unibody/suspension with the Camaro and Nova, parts for these cars should also work if you are not the fabricator type.

This part?

http://www.earlyfirebirds.com/products/67-traction-bars

or at least one of the brackets on the end of it?

Perhaps.