This is a standard 289-2V/4V C3AE connecting rod with 5/16-inch bolts. The only difference between this rod and a Hi-Po rod is bolt size. It's exactly the same forging. The '69-'70 Boss 302 uses this same forging with 3/8-inch bolts. Displacement comes from using a different crank in the Boss 302 with a 3-inch stroke.