Valve markings

[Rat]

Probably a dumb question without a legitimate answer...
What are the numbers on the valve heads (may be a stock valve only thing idk)

What I mean is my 208's original head has RI/RE which I know what those are but not the 210 below them. The Predator Hemi Head has 170 below the RI/RE.

Anyone know?

 

[bob58o]

Maybe something to do with the engine block.
168, 170F, 188F, 190,…

Im not sure what those numbers mean either, but 170 seems like it’s not random.

The Hemi block I have now says G210FA

 

[Rat]

Maybe something to do with the engine block.
168, 170F, 188F, 190,…

Im not sure what those numbers mean either, but 170 seems like it’s not random.

The Hemi block I have now says G210FA

I meant to post a pic in the original post. The thing about the 212 Hemi it's off of is that it's an OG that doesn't seem to have any hemi specific parts aside from the physical head and rockers.
Even Non hemi springs fit properly in the spring seats