? about 360 crankshaft.

And Crankshaft Supply shows the same crank from 1971 to 2003, replacing the 2 common PN's of 360 cranks for all years. Not notes are there for any balance change. So it obviously is the same crank. And I have found 3 other references that show the same crank PN's for LA and Magnum. The OP might want to call a company like Crankshaft Supply and ask, as suggested. 612-521-2235

http://crankshaftsupply.com/crankcatalog.htm

They also show 2 rod PN's for LA vs Magnum which all makes sense.

Here is some bobweight data:
An Error Has Occurred!

FWIW, I am at the point after researching this that I would install it with confidence, with the same LA rods and pistons, etc., with the LA flexplate and damper.