I measured a 67-72 & a 73-87, one hole on the frame mount lines up with a rivet holding the radiator x-member, drilled it out & temp mounted bar to locate the remaining hole in the frame. Most 66's I find have pre-drilled lower A arms, my 64 I had to drill the lower arms.
If you like to go around corners, grab a 1 ton or suburban front bar(larger diameter) & add a rear bar.
