WHAT DOES B16A2 MEAN?

I bought my MRS 3sgte back in 2020. Parker from NW Motor s identified as me and advised me I had been acquiring a 1-of-a-kind, clean 3sgte motor. and he didn’t lie. I’ve bought the pictures to demonstrate it ahead of installation. I haven't noticed a motor this clean. Seems like it just came from the assembly line.Initially, it is vital to real