Not to bump my own thread but in case someone comes across this in the future and is curious about choosing the correct bearings...see this link.
https://www.bimmerworld.com/Engine/B...4-N55-S55.html
Here's the important part:
"Engine manufacturers, including BMW, color-code their bearing parts to match crankshaft and connecting rod sizes. This pair of bearings include 1 upper Violet and 1 lower Blue bearing. This combination is known as the "B Classification". BMW also used a R Classification for Yellow/Red bearings. You must check the front face of the first crankshaft counterweight to determine which bearings are in your engine. Each engine can have different mixtures of R or B bearings. New bearings must match the originals being removed!
Bearings are also sold by size. These are the standard 56.0mm inside diameter size.
Note: connecting rod bolts cannot be re-used. They are stretch-to-yield and must be replaced."
