25 psi with a drill/primer tool is good IMHO.

as you know when it is running it will be at xxx on the gauge cold, then drop to xxx when hot.

10psi per 1000rpm is the rule of thumb..so no way a drill is turning it 1000 rpm so 25 psi is good on a slow drill.

when it is at idle at xx rpm and gauge shows xx on gauge, then rpms go up you see the gauge go up in the 40-60 psi range..higher when cold 70-80 psi.

this is what my fresh 318 shows so they will fluctuate some on psi due to gauge quality.

I have swaped a few flat tappet cams out of a roller block and go to stock roller lifters and visa-versa just need the correct pushrods.

the lifter bore is taller for the roller lifters and dogbones which fit into the machined top of the lifter bores. flat tappets do drop down in the bore but still should be the same as a non roller block.

can you post a pic of the oil hole not coverd??

I have a engine on the stand mocked up but no flat tappet lifter to drop in to compare them.