im planning on doing a th400 swap
They also came with bellhousings to fit everything from chevys, buick/olds/pontiac, jeeps, jaguars, etc. It's not worth trying to adapt a non chevy bellhousing to an LS engine.
Not sure what the going rate in CA is, but a used core sells for 75.00 in the detroit area.
Regardless what core you but its most likely going to need internal hard parts.
If I had a choice between buying late or early I guess I would buy a later core.
Look for heat treated splines on the pump stator.






