FYI, my 91 pre-mag roller cam engine has oil thru roller lifter with hollow rods oiling the rockers at the same time it oil up thru the LA heads to oil the shaft and rockers.

I am not sure if oil thru lifters and hollow pre-mag push rods would be enuff oil to the shaft mount rockers.

looking at mine it seems to be oiling them plenty but then again it is oil 2 ways.

if I had a JY magnum engine to run a set of LA heads with it oiling the rockers by lifters/PR only I would give it a shot myself.

you could go first on the testing if you like..?

seems to be enuff oil supply to magnum rockers on a pedistal mount.