ARP 8740 1/2" Head Stud Kit - 2003+ LS 427 LS The 558-416 is an adapter

The 558-416 is an adapter harness that can be used to adapt any LS harness that uses an LS1/2 MAP sensor connection to an LS3 MAP

12″ (3 mm)

Buy it for yourself or as a lovely gift for your friends and family

0L blocks open up more options for better flowing cylinder heads

ARP 8740 1/2" Head Stud Kit - 2003+ LS 427 LS The 558-416 is an adapterBoostline Performance in combination with ARP Fasteners has put together an affordable 1 2" head stud set for 03+ Gen III and Gen IV LS engines! These 1 2" Studs are made from ARP 8740 material, adding additional clamping force and head gasket stability for boosted applications on stock blocks. Any Boostline Engine package can be drilled and tapped for this 1 2"stud option! Or you can do it yourself by drilling tapping Tick Performance drilling