Pro/Stock was a generic line that came out in the 70's and was sold thru Performance Warehouse Distributors across the country as a low price leader,the products were made by various companies they were only around for a short time and faded away in the early 80's.They were a short line which consisted of plug wires,valve covers and headers,I sold a fair amount of them at first and the quality was good,no comebacks that I can remember .