This is what I run, https://drivenracingoil.com/i-30497805-hr4-10w-30-synthetic-hot-rod-oil.html This has been discussed many times here, https://www.v8buick.com/index.php?threads/new-oil-tech.222499/
Stuff as much compression in it as you can. Go for near zero or zero deck. Do the oil mods. Roller cam is EXPENSIVE! I do know with a roller cam and Molnar rods, you HAVE to do grinding on the rods, some rods WILL hit the cam lobes, NOT sure if thats the case with cap screw rods, or nut and bolt rods. I switched from the crappy Morel roller lifters to Johnson, ANOTHER near 800 bucks. Flat tappet should do well, much cheaper! CHECK CHECK CHECK all clearances! Measure for proper pushrod length too. Install ALL TA back grooved cam bearings, not just #1, #1 IS the most important BUT the installation of the rest of the TA back grooved bearings will insure proper oiling for the rest of the cam journals.