ARP rod bolts/nuts for the 60V6 2.8, 3.1, 3.4, 3100, 3400, and 3.4 DOHC connecting rods. These are an excellent upgrade for the money, especially when compared to the cost of new stock replacement rod bolts. Cutting the rod caps and resizing the big end is required.
The description from ARP as follows.
A premium grade 8740 alloy chrome moly steel is used to manufacture ARP® High Performance connecting rod bolts. This material is heat-treated to provide a tensile strength in the 200,000 psi range, which is substantially stronger than the OEM bolts. Cycle testing shows ARP® High Performance rod bolts to be nearly five times more reliable than stock bolts