Here's a thought on oil viscosity

famous bob said

I run hughs BUSHED rockers, and have full time oiling to them. I did take a member on here`s suggestion and did it in the lifter galley, by drilling into the oil feed passages. BIG MISTAKE ! A much easier and better way would be to slightly groove the # 4 cam bearing journal, u could get rid of it if u didn`t like it by changing cams. The way I did is a fair amount of trouble to undue .

Click to expand...

perhaps not
when i was younger i worked at a place rebuilding VW diesel engines
one of the things we did was reroute a certain oil passage to the head, because it was a spot where the block was prone to cracking

we had these machined aluminum plugs we would locktite and drive into the block
that would block the passage, and then we would tap into a different passage and run a line around the outside of the block

what im saying is, you might be able to drive a plug in the custom holes to undo it