This is what was in the engine when I got it. Pushrods were shorter than Magnums for the LA heads, of course:
While I don't deny that at least 8 lifters had been swapped out on this engine when I got it (or Mopar installed different batches on each side - wouldn't rule it our), I highly doubt that all 16 pushrods had been changed to oil-throughs. That, and prior to this year, that engine lived its life with it's factory TBI injection system inside a B350 high-top camper conversion. Probably the last vehicle on earth that would get modded, unless Roadkill had bought it.
That said, there's no reason the Magnum lifters shouldn't work - and I've already proven that oil does effectively get to the lifters.