This is a JW Ultra Bell. Replaces the stock bell housing on a powerglide. Bolts to the transmission pump. It’s an SFI certified bell and has a SBC bolt pattern. I think it will bolt to an LS engine as well with either one bolt hole not used or one bolt hole not there. I’m not a Chevy guy so I’m not sure. This came brand new on a powerglide I bought to put behind my SBF, so I don’t need this bell. I used the bolts to install my SBF JW Bell, so they aren’t included.