The oil tube is supposed to be pinched. It allows more oil pressure.
For years, my dad and I never had the measuring guages for setting the rockers. We would set them by ear and feel. I bet some experienced guys on here may cringe at my saying that, but that's what we did and it worked well for us.
With the engine running and warm, we would have all the jam nuts loosened to where we could turn the setting screws and would ease the lifter adjustment till it just stopped tapping.
Once the entire line was done, we'd check the response of the engine but throttling the carb. After we were satisfied, we tightened the jam nuts.
I'm glad you got your new rocker shaft. Good job on the assembly of it! You're almost there.
Jerry
