The other thing is....... if that one lifter bore was tapered before the rollers were installed....... that could be the whole cause of it.
Allowing some movement of the lifter, in a way that wouldn’t normally be able to happen.
That is one thing I am wondering, and plan on checking out. And then, if it is tapered I will wonder if that is what caused the problem, or if the fact that the lifter spun and was still going up and down caused the bore to taper...?
Brian said he felt it happen while driving. He did call me about it and I asked how the oil pressure was. Long story short, I told him to drive it home.