The Parts Guy
The cam followers on the 4.6 rotate; they're roller followers. The lash adjusters do not. It's a completely different animal compared to a flat tappet OHV arrangement.The other link is interesting too. I wasn't aware not to use synthetic oil when breaking in flat tappet cams. Or that synthetic oil may not allow the lifers to rotate.
Do the followers on the 4.6 rotate?