A518 lock up conversion

I stopped by my buddys shop to check on my 46RH trans build. He told me its done but I need to tell buy the kit I want and drop it off. I looked at the kits and the OD engagement points are either 44 or 50 MPH and the Lock Up points are 50 and 52 MPH. The car has a 318 2brl now but ultimately will have a very healthy stroked 5.9. The car is a toy and will 99.999% be driven on the street. I think OD at 50 and lock up the same. I am not a trans guy so I don't know if that's where the points should be. I appreciate y'alls input.