? about 360 crankshaft.

Seems like that could effect oil pressure as well as the amount of oil thrown at the rings....
Understood, and I had the same exact concern with the wide ride side clearances. But with those wide side clearances, our 340 runs 30 psi hot at 750 RPM idle in gear with 10W30 (using the HV oil pump), so it does not effect pressure that I can see. An no oil burning in 800 miles with just a good quality moly top ring set.

And if the OP is using the LA rods, then if they fit on the Magnum crank with decent side clearances, then it is not an issue.