Issues with pre - 70's 318 in a 73 Duster

Will the the timing cover directly swap out?

You can get new timing chain covers for the 70 and later configuration from Mancini Racing...

Timing chain covers are offered separately or in packages with the gaskets, bolts, and water pumps included.... Just look here for the option that you prefer:

Timing Covers


aluminum water pump with six blade impeller:

Aluminum Water Pump


aluminum water pump with 8 blade impeller:

Aluminum Water Pump


You can save some money if you need to by buying them used, they are not hard to find the later 70's style timing chain covers and water pumps...

Or use the old ones from your 73 if you still have them...