On one of the motors I put together using Jesel rockers, I thought I'd be a smart guy and go with pushrod oiling.
It was built from an aluminum World block with bushed lifter bores, so I got some Comp 892's for it.
Had it all together, primed the motor....... And as soon as the drill bogged a bit from building oil pressure in the system, oil shot out of the top of one of the rockers 15-20 feet across the shop.
Apparently, the hole in the bushing and the hole in the lifter were lined right up with each other when the cam was on the based circle.
With the drill even barely turning oil just gushed out of whichever rockers were mostly closed.
When I saw it my thought was, "well....... I guess that's not going to work".
That was completely unrestricted oil flow to the top end.

Ordered some 87019's(no oil holes) and spray bar valve covers..... And that was that.