Product details:
Chevy Big Block. 1.72:1 ratio with 7/16 stud diameter. Extra large full needle bearing trunnion Withstands spring pressures up to 700 lbs Chrome-moly push Rods recommended Elgin Pro stock high performance stainless steel roller rocker arms for Chevy Big block. 1.72: 1 ratio with 7/16 stud diameter.