If there is a part number change, there is a reason for it. There is **nothing** arbitrary about Toyota informational logic systems. Conversely, if there is no part number change there is a reason for that as well. There are parameters for how/when/why Toyota part numbers change or don't. Everything is codified in Toyota Engineering Standards (it's a massive, massive document-- thousands of pages of minutiae detail about everything from fonts for branding, packaging protocols and materials, minimum standards for material sciences in every possible application, etc. It's a **deep** document).