help identify this transmission. Supposed to be A518

Thanks for the pic. I checked the shafts when I brought it but was just wondering how to tell if the converter is a lock up.
I might just have to run it. It should be fine to use on the magnum as long as I pull the big weight off.

Lockup and non-lockup converters won't interchange. Different spline counts. In other words if the trans is a lockup model you will not be able to get a non-lockup converter to slide in. It might go a little way in but not all the way.