ARP 135-3707 - Cylinder Head Bolt Kit, HP Series, 12pt, BBC Heads w/ Mark V, VI Iron Blocks (4 long exhaust bolts per head)ARP 135 3707 Cylinder Head Bolt Kit, HP Series, 12pt, BBC Heads w Mark V, VI Iron Blocks (4 long exhaust bolts per head). ARP Cylinder Head Bolt Kit, HP Series, 12pt, BBC Heads w Mark V, VI Iron Blocks (4 long exhaust bolts per head) This kit will fit most conventional style Big Block Chevy head with 4 longer exhaust bolts World Products Merlin iron or early aluminum, Late bowtie aluminum, Dart Aluminum, Pro 1, Pro TopLine, AFR Line heads (All Black