WHAT DOES B16A2 MEAN?

I bought my MRS 3sgte again in 2020. Parker from NW Motor s identified as me and explained to me I had been obtaining a a single-of-a-type, thoroughly clean 3sgte motor. and he didn’t lie. I’ve obtained the pictures to demonstrate it before installation. I have never found a motor this clear. Seems like it just came off the assembly line.It’s