Yes differant oil pan. The rear of the pan is a differant size than the others. However later on Chrysler changed the 5.2(318) magnum to use the 5.9(360) pan.
The heads on the early 360s were some of the same used on the low compression 340s. Some of them were 1.88 J heads.
The windage tray used on the 360 has wider spaceing for the mounting bolt holes.
This was Accomplished two ways. The first way was they made a separate windage tray for the 360. The second way was they slotted or oblonged the mounting bolt holes of the 340 tray so that it fits both motors.
Because of the larger main bearings they had to move the main cap bolts farther apart.
My list of differances
Larger mains equals larger main bearing and a larger rear seal.
Differant oil pan
Differant mounting holes for windage tray
I have also found the 360 main cap bolts to be about 1/4 onch shorter but not alway
