Push rod oiling is enough, provided the rockers you have are drilled for through oiling and have oiling adjusters in them. Test them ALL with an air hose when you know about where the adjuster will wind up with proper lash. The groove in the adjuster oils best at about two turns in from full out. Occasionally TD forgets to cut the groove behind the bearings that allow oil to pass though the body to the tip. That's why you should test them all.

If you have wide main, and rod clearance with a main priority oiling block the front lifter pairs left, and right will benefit from a very small slot cut in the tappets connecting the oil hole to the oil band. At idle, with a vacuum pump, they'll be no oil up there on those cylinders without it.