Product Description Specifications With a 2024 aluminum rocker and 8620 hardened steel shaft, this shaft-mount rocker system adds stability to the engine which frees up horsepower. This system features 1.7 ratio rockers for BBC w/ Brodix 2 Xtra heads. Category: Engine Components>Rocker Arms Core: N LTL: N MPN: 1507CPG Proposition 65: Y Special Order: Y