Jianis,
Yes, it was possible to convert a 216 to use precision insert bearings in the early 1950s. Here is a page from the
Wayne catalog from 1954. It was also fairly common to convert the low-pressure, splash oiling of the connecting rod bearings to full-pressure lubrication, as also shown in
Page 15 of the Wayne catalog.
Does your engine still have the splash system? I thought that a rod dipper is visible in your linked photo,
Hoyt
