70/74 wiring doesn't really changes at column. Of course 70 column is diff due the locking system, but not on the electrical related to plugs at least. Sure ign and turning switches got their physical diff too on 70 with the rest ( also first 71s turning switches ), but still plugs remain the same so all years will plug between them.

As far I know, all 71/74 will interchange on E bodies being plug and play.