aftermarket from who? these have been bolted to a bumper in my garage for over 20 years and that bumper has round holes where the stud goes through not square like all off the other 70/71 bumper i have ever owned or have seen. i took it off the car myself and just never thought anything of it until i started going through stuff while cleaning and noticed to stamping on the bottom. i though they were just added by someone from a b or c body because they were much bigger.