340 heads on 360?

So i have a 1973 Duster that was originaly a 340 4-speed. unfortunately at some point in its life the engine froze and it cracked the 340 block. now it has a 360 out of a 1980's Ram with the 73 heads on it. i'm just wondering if and what 340 heads change on the 360. does it increase compression?, does it have bigger intake valves? or something, just general questions.
im kinda new too this so yeah.

Thank you,
-Elís M