Feature●Constructed of the finest .041 copper material and will seal where most gaskets fail●Collector gaskets include stainless steel fasteners●Heat-treated header bolts featuring 3/8"-16 x 1" threads, a hex head, and a black oxide finish●Fits tube headers onto AMC 290-401, small block Chevy 262-400, big block Chrysler 383-400●Set of 12 boltsDescription