To paint or not to paint?

Very little about Chrysler was ever carved in stone but as a general rule of thumb...
Their industrial grade engines with a forged steel crank were painted Chrysler Industrial Red.
Majority of blue engines will have cast iron cranks.

Can't apply to 340s though, because 'none' of them had cast cranks. At least there is no factory p/n for a cast 340 crank, that I know of.