I made the mistake of trying to use a set of the original Pro Part headers on my 1969 383 Dart GTS 4 speed car they where not designed to be used on low decks in A bodys High deck motors only I'm not sure about the new ones Mazolini is selling now I ended up buying a set of the MustangEDITED, There Maddod headers, not Mustangs, sorry ) two inch low deck headers for that car, I haven't gotten around to swapping them into the Dart yet, maybe this spring I'm planning on installing them to check the fit and if I like them I will take them back off and have them coated black like the Pro Parts are now