This listings is for a set of (16) 3/8"-24 Thread Top End and 7/16"-14 bottom end thread screw in the studs. These are Straight shaft & have NO hex nut. Theses are designed to replace the stock style press-in studs on small block Chevy V8 engines without having to machine the stud boss down on the head. Just pull the old studs and tap the holes to 7/16"-14 coarse threads. 2.325" Overall stud length 1.600" Stud height .725" Screw-in thread depth .875" Adjuster thread depth, 3/8"-24 Fine thread tops and 7/16"-14 Coarse thread bottoms.