machined valve cover rails screw-in rockerarmstuds bolts on to 1987-94 mustang ... jr or 2.020 windsor sr x 1.600 rockerarmstuds accepts 7/16 screw-in studs ... 7° chrome moly retainers recommended installation items rockerarms aftermarket roller ... rockerarms recommended however if stock rockers ... are to be retained use stud mounted rockers head gaskets fel-pro #9333pt or #1011-2 ...