3441405 is a stamping number not the actual Chrysler part catalog number.
All non ac motors interchange from 68 thru 74.
This is a list of the catalog part numbers:
2837678 - 1968,1969
3420859 - 1970,1971,1972
3621837 - 1973,1974
Each number supersedes the earlier number.
Four Seasons 35504 aftermarket motor shows as a replacement for the above numbers but you would need to use the connectors from your old motor.