There's a better way to supply full-time oiling to the rocker shafts rather than grooving the #4 cam journal, but requires block work prior to assembly. Drill a small hole in the valley between the vertical top-end oiling channel and the horizontal oiling channel for the lifters. Then tap the hole and cap the hole with a set screw with thread sealant. Follow-up with oil restrictors at the deck or in the heads, Carter carb jets can work for this. The rockers now feed off the lifter oil galleys, and the #4 main, #6 rod, and #7 rod don't see a pressure drop when the cam holes line-up. You can go one step further and block the vertical oiling passage between the #4 main and the #4 cam bearing, for the #4 cam bearing now gets additional oiling from the lifter galleys making the oil supply to the #4 cam redundant. It's not a necessary step.

Doug Herbert still offers the original solid roller lifters designed by Chet. They're heavy and robust with a large wheel and needles, but no pin oiling. I like them for moderate applications. USA made and under $400. Not the best, but not the worst.
https://www.herbertcams.com/bb-chrysler-vertical-bar-solid-roller-lifters/