Trick Flow heads on 5.9 Magnum block
I put Edelbrock LA-type heads on a late Magnum block (rocker oil passage not drilled) and made my own external rocker oiling setup based on a similar thing
@Toluene56 did on his engine (I believe he used Speedmaster heads on Magnum block). My build thread:
https://www.forabodiesonly.com/mopa...magnum-edelbrock-la-heads-build.418466/page-4
Shaft-mount rockers are designed to have constant (or nearly constant) pressurized oil fed at the fulcrum point on the underside of the rocker shaft. Trying to oil through the pushrods into the rockers might work if the aftermarket rockers have internal passages for that but I personally would still want pressurized oil inside the shafts. I guess that's your call.
Or if the block is disassembled just have the passage drilled to oil the rocker shafts; all Magnum blocks came with the passages cast into the valley it's just the later ones (1996-ish and up?) didn't have the passage drilled from the factory. I didn't feel like disassembling my short block so I did it the complicated way lol.