Years ago we did what was a converter flush, using a machine under air pressure and a cleaning agent, if you can find a long time transmission shop
they may still do it. The major things to address are, 1) the neck is not damaged, 2) internal pump splines are not stripped and the one way clutch
internally functions. Most of the time they were still good, you could also turn them in as cores, or as you stated use as paper weights (haha)
70-Conv_4sp
