Magnum 360

Slightly, yes, nothing to whoop and howl about. The Magnums have a hair bit more compression, the head advantage is slight, maybe a bit more noticeable if you compare it to a mid 70's mill.
And of course the roller cam and 1.6 rockers.

Whatcha thinking about? A lot depends on what and how you equip it over the OE set up. On my 5.9, I just added some bolt on parts for now.

RPM intake
650 Edelbrock AVS
1-3/4 - 2-1/2 exhaust
MP chrome box
vacuum advance distributor
Im waiting on funds for a cam & converter.
It is a 360/380 create engine copy. Except for the small carb (for now) & the RPM intake which will stay.