Originally Posted by aznitronut

Here is a link to amainhobbies.com, for the rear bearing for the WS7 III, and most of the RB engines. The front bearings are all the same size. The C5 and C6 main bearings are a different size. RB Concept 13x25mm Rear Bearing for Square Stroke (E/S5/S7II/WS7II) Engines
[RBC01150-13S]