LA Cam Swap In A Magnum?

No issues.
Sounds like you've already got the rocker oiling taken care of, and since you were running the EQ heads and rockers on the LA, the cam specs shouldn't change (1.5 LA vs 1.6 Magnum). Everything should just swap over, unless you've got some different deck or head machining done on one block or the other- then it's just a matter of getting different length pushrods.